feat(vsc): show count in sample gallery type filter

[tecton]

Effect:

Feature: https://dev.azure.com/msazure/Microsoft%20Teams%20Extensibility/_workitems/edit/33259089

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.02%. Comparing base (f3948d0) to head (a40d8d8).
Report is 2 commits behind head on dev.

Additional details and impacted files

@@           Coverage Diff            @@
##              dev   #14238    +/-   ##
========================================
  Coverage   90.02%   90.02%            
========================================
  Files         647      647            
  Lines       38860    38860            
  Branches     7815     7612   -203     
========================================
  Hits        34984    34984            
  Misses       1755     1755            
  Partials     2121     2121            

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