[configcompression] make IsCompressed a member function

[TylerHelmuth]

Description:
Updates IsCompressed to be a member function.

Link to tracking Issue:

Closes #9434

Testing:

Documentation:

Please delete paragraphs that you did not use before submitting.

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (f37e376) 90.24% compared to head (8cacfc9) 90.25%.
Report is 4 commits behind head on main.

Files	Patch %	Lines
config/configcompression/compressiontype.go	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9435      +/-   ##
==========================================
+ Coverage   90.24%   90.25%   +0.01%     
==========================================
  Files         344      344              
  Lines       17932    17957      +25     
==========================================
+ Hits        16182    16207      +25     
  Misses       1421     1421              
  Partials      329      329              

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