fix display of branch names with special characters

[isc-pbarton]

Fixes #914

Testing plan

docker compose exec iris iris session iris
do ##class(SourceControl.Git.API).Configure() to initialize a git repository
docker compose exec iris bash
cd /usr/irissys/mgr/repo/USER
git branch "invalid#branch"

load the web ui: http://localhost:52774/isc/studio/usertemplates/gitsourcecontrol/webuidriver.csp/USER/

• the branch list in the left panel should show a warning message that there is a branch with unsupported characters.
• I should be able to create new branches with the supported characters.
• I should not be able to create new branches with the unsupported characters, and I should get a descriptive error message if I try.

[isc-pbarton]

CI failing I think because of changes in the intersystemsdc/iris-community:latest image. Fails to install TestCoverage. When I run locally on the same base image I get an error that no IPM registries are configured.

[isc-dchui]

Hm I'm not fully convinced we should necessarily support the "#" character (or spaces) in branch names. I feel like as long as we support this we're fine.

[isc-pbarton]

After discussion with @isc-dchui, we decided that just supporting pound sign is kind of arbitrary, but we want to keep the web UI simple rather than supporting everything. Plan is:

• support smaller set of branch names matching this default set
• add branch name validation when you create a new branch, both in web UI and source control menus
• exclude unsupported branch names from web UI, and show warning message if more branches exist with unsupported names. this keeps us reasonably compatible with other git clients

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 49.10%. Comparing base (ee80d7f) to head (d2eaff4).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #956      +/-   ##
==========================================
+ Coverage   49.05%   49.10%   +0.04%     
==========================================
  Files          23       23              
  Lines        3284     3287       +3     
==========================================
+ Hits         1611     1614       +3     
  Misses       1673     1673              

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[isc-dchui]

Just one thing and a question about testing. What kind of testing did you do for this change?