Add API to set title of generated UI

[GDYendell]

Example usage: DiamondLightSource/fastcs-odin@a042360

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 43.99%. Comparing base (fb929a1) to head (b6ac0f1).

Files	Patch %	Lines
src/fastcs/backends/epics/gui.py	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #36      +/-   ##
==========================================
+ Coverage   43.91%   43.99%   +0.08%     
==========================================
  Files          20       20              
  Lines         690      691       +1     
==========================================
+ Hits          303      304       +1     
  Misses        387      387              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.