Expose Firestore WebSocket port in hub. Fixes #5051.

[yuchenshi]

Description

Fixes #5051
Fixes firebase/firebase-tools-ui#863

Scenarios Tested

Manually started the suite + UI, and tested on UI. The Requests tab no longer show errors and can display operations again.

Sample Commands

[codecov-commenter]

Codecov Report

Base: 55.76% // Head: 55.75% // Decreases project coverage by -0.00% ⚠️

Coverage data is based on head (9f6a51c) compared to base (655f8e8).
Patch coverage: 0.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5081      +/-   ##
==========================================
- Coverage   55.76%   55.75%   -0.01%     
==========================================
  Files         305      305              
  Lines       20522    20524       +2     
  Branches     4142     4144       +2     
==========================================
  Hits        11444    11444              
- Misses       8096     8098       +2     
  Partials      982      982              

Impacted Files	Coverage Δ
src/emulator/firestoreEmulator.ts	22.22% <0.00%> (-0.86%)	⬇️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.