Implement filtering in branch list screen

Branch list screen should have the same filtering as Project and Group
list screens. The filtering is done using the branch short name,
which is what is displayed in the list (not the full reference). When a
user adds a new branch, it will be displayed if there is space and if
it matches the filter.

Change-Id: I4e743691bba7b873697fb53899dbdf4589fc0e56
3 files changed