UI: Show a 'loading' chip when tasks are being loaded

Currently, 'No Tasks' is shown in the tasks summary section when the
API to fetch the tasks is in progress. Show a 'loading' chip instead.

https://imgur.com/a/hSTtmRx

Change-Id: Ie89cc9276ac4c5e3f47aec3b0831636feb781cdc
3 files changed