Minor cleanup for new data entry points

[shobhitagarwal1612]

Performs a minor refactor on #2892 to further remove non-composable logic out of the composable class.

This is a pure refactor and doesn't change the behavior. Verified by running the app locally.

@sufyanAbbasi PTAL?

[codecov]

Codecov Report

Attention: Patch coverage is 20.00000% with 8 lines in your changes missing coverage. Please review.

Project coverage is 62.97%. Comparing base (06f4dd1) to head (2d32ba4).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
...und/ui/home/mapcontainer/jobs/JobMapComposables.kt	25.00%	4 Missing and 2 partials ⚠️
...ome/mapcontainer/HomeScreenMapContainerFragment.kt	0.00%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #3036      +/-   ##
============================================
- Coverage     62.99%   62.97%   -0.02%     
+ Complexity     1289     1287       -2     
============================================
  Files           273      273              
  Lines          6731     6723       -8     
  Branches        935      933       -2     
============================================
- Hits           4240     4234       -6     
  Misses         1872     1872              
+ Partials        619      617       -2     

Files with missing lines	Coverage Δ
.../java/com/google/android/ground/util/ComposeExt.kt	37.50% <ø> (+4.16%)	⬆️
...ome/mapcontainer/HomeScreenMapContainerFragment.kt	17.26% <0.00%> (-0.13%)	⬇️
...und/ui/home/mapcontainer/jobs/JobMapComposables.kt	14.62% <25.00%> (-2.20%)	⬇️