Add command to test on safari/firefox too

`yarn test:browsers` will run the tests on all browsers:
https://imgur.com/a/3c4K0Xf

Some fail due to browser differences, so this is not the command the CI
uses to verify changes.

It will likely fail at first and tell you to install the system
dependencies for the other browsers using the playwright command:
https://playwright.dev/docs/cli#install-system-dependencies

Release-Notes: Run web tests on other browsers via test:browsers command
Change-Id: Ie8a39df32fc5fce83ec196c02f99987b1b19b870
diff --git a/polygerrit-ui/yarn.lock b/polygerrit-ui/yarn.lock
index ca6943d..35409a8 100644
--- a/polygerrit-ui/yarn.lock
+++ b/polygerrit-ui/yarn.lock
@@ -965,7 +965,7 @@
     "@jridgewell/sourcemap-codec" "^1.4.10"
     "@jridgewell/trace-mapping" "^0.3.9"
 
-"@jridgewell/resolve-uri@^3.0.3":
+"@jridgewell/resolve-uri@3.1.0", "@jridgewell/resolve-uri@^3.0.3":
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/@jridgewell/resolve-uri/-/resolve-uri-3.1.0.tgz#2203b118c157721addfe69d47b70465463066d78"
   integrity sha512-F2msla3tad+Mfht5cJq7LSXcdudKTWCVYUgw6pLFOOHSTtZlj6SWNYAp+AhuqLmWdBO2X5hPrLcu8cVP8fy28w==
@@ -975,11 +975,19 @@
   resolved "https://registry.yarnpkg.com/@jridgewell/set-array/-/set-array-1.1.2.tgz#7c6cf998d6d20b914c0a55a91ae928ff25965e72"
   integrity sha512-xnkseuNADM0gt2bs+BvhO0p78Mk762YnZdsuzFV018NoG1Sj1SCQvpSqa7XUaTam5vAGasABV9qXASMKnFMwMw==
 
-"@jridgewell/sourcemap-codec@^1.4.10":
+"@jridgewell/sourcemap-codec@1.4.14", "@jridgewell/sourcemap-codec@^1.4.10":
   version "1.4.14"
   resolved "https://registry.yarnpkg.com/@jridgewell/sourcemap-codec/-/sourcemap-codec-1.4.14.tgz#add4c98d341472a289190b424efbdb096991bb24"
   integrity sha512-XPSJHWmi394fuUuzDnGz1wiKqWfo1yXecHQMRf2l6hztTO+nPru658AyDngaBe7isIxEkRsPR3FZh+s7iVa4Uw==
 
+"@jridgewell/trace-mapping@^0.3.12":
+  version "0.3.17"
+  resolved "https://registry.yarnpkg.com/@jridgewell/trace-mapping/-/trace-mapping-0.3.17.tgz#793041277af9073b0951a7fe0f0d8c4c98c36985"
+  integrity sha512-MCNzAp77qzKca9+W/+I0+sEpaUnZoeasnghNeVc41VZCEKaCH73Vq3BZZ/SzWIgrqE4H4ceI+p+b6C0mHf9T4g==
+  dependencies:
+    "@jridgewell/resolve-uri" "3.1.0"
+    "@jridgewell/sourcemap-codec" "1.4.14"
+
 "@jridgewell/trace-mapping@^0.3.9":
   version "0.3.15"
   resolved "https://registry.yarnpkg.com/@jridgewell/trace-mapping/-/trace-mapping-0.3.15.tgz#aba35c48a38d3fd84b37e66c9c0423f9744f9774"
@@ -1883,6 +1891,16 @@
     picomatch "^2.2.2"
     v8-to-istanbul "^8.0.0"
 
+"@web/test-runner-coverage-v8@^0.5.0":
+  version "0.5.0"
+  resolved "https://registry.yarnpkg.com/@web/test-runner-coverage-v8/-/test-runner-coverage-v8-0.5.0.tgz#d1b033fd4baddaf5636a41cd017e321a338727a6"
+  integrity sha512-4eZs5K4JG7zqWEhVSO8utlscjbVScV7K6JVwoWWcObFTGAaBMbDVzwGRimyNSzvmfTdIO/Arze4CeUUfCl4iLQ==
+  dependencies:
+    "@web/test-runner-core" "^0.10.20"
+    istanbul-lib-coverage "^3.0.0"
+    picomatch "^2.2.2"
+    v8-to-istanbul "^9.0.1"
+
 "@web/test-runner-mocha@^0.7.5":
   version "0.7.5"
   resolved "https://registry.yarnpkg.com/@web/test-runner-mocha/-/test-runner-mocha-0.7.5.tgz#696f8cb7f5118a72bd7ac5778367ae3bd3fb92cd"
@@ -1891,6 +1909,15 @@
     "@types/mocha" "^8.2.0"
     "@web/test-runner-core" "^0.10.20"
 
+"@web/test-runner-playwright@^0.9.0":
+  version "0.9.0"
+  resolved "https://registry.yarnpkg.com/@web/test-runner-playwright/-/test-runner-playwright-0.9.0.tgz#c13b71ecfe763ae5d15dff586a35a9840c238b1f"
+  integrity sha512-RhWkz1CY3KThHoX89yZ/gz9wDSPujxd2wMWNxqhov4y/XDI+0TS44TWKBfWXnuvlQFZPi8JFT7KibCo3pb/Mcg==
+  dependencies:
+    "@web/test-runner-core" "^0.10.20"
+    "@web/test-runner-coverage-v8" "^0.5.0"
+    playwright "^1.22.2"
+
 "@web/test-runner-visual-regression@^0.6.6":
   version "0.6.6"
   resolved "https://registry.yarnpkg.com/@web/test-runner-visual-regression/-/test-runner-visual-regression-0.6.6.tgz#4a4dc734f360cba66a005e07b4a1c0a9ef956444"
@@ -4626,6 +4653,18 @@
   dependencies:
     find-up "^4.0.0"
 
+playwright-core@1.27.1:
+  version "1.27.1"
+  resolved "https://registry.yarnpkg.com/playwright-core/-/playwright-core-1.27.1.tgz#840ef662e55a3ed759d8b5d3d00a5f885a7184f4"
+  integrity sha512-9EmeXDncC2Pmp/z+teoVYlvmPWUC6ejSSYZUln7YaP89Z6lpAaiaAnqroUt/BoLo8tn7WYShcfaCh+xofZa44Q==
+
+playwright@^1.22.2:
+  version "1.27.1"
+  resolved "https://registry.yarnpkg.com/playwright/-/playwright-1.27.1.tgz#4eecac5899566c589d4220ca8acc16abe8a67450"
+  integrity sha512-xXYZ7m36yTtC+oFgqH0eTgullGztKSRMb4yuwLPl8IYSmgBM88QiB+3IWb1mRIC9/NNwcgbG0RwtFlg+EAFQHQ==
+  dependencies:
+    playwright-core "1.27.1"
+
 pngjs@^6.0.0:
   version "6.0.0"
   resolved "https://registry.yarnpkg.com/pngjs/-/pngjs-6.0.0.tgz#ca9e5d2aa48db0228a52c419c3308e87720da821"
@@ -5555,6 +5594,15 @@
     convert-source-map "^1.6.0"
     source-map "^0.7.3"
 
+v8-to-istanbul@^9.0.1:
+  version "9.0.1"
+  resolved "https://registry.yarnpkg.com/v8-to-istanbul/-/v8-to-istanbul-9.0.1.tgz#b6f994b0b5d4ef255e17a0d17dc444a9f5132fa4"
+  integrity sha512-74Y4LqY74kLE6IFyIjPtkSTWzUZmj8tdHT9Ii/26dvQ6K9Dl2NbEfj0XgU2sHCtKgt5VupqhlO/5aWuqS+IY1w==
+  dependencies:
+    "@jridgewell/trace-mapping" "^0.3.12"
+    "@types/istanbul-lib-coverage" "^2.0.1"
+    convert-source-map "^1.6.0"
+
 valid-url@^1.0.9:
   version "1.0.9"
   resolved "https://registry.yarnpkg.com/valid-url/-/valid-url-1.0.9.tgz#1c14479b40f1397a75782f115e4086447433a200"