[ACA-1606] use new api siteservice

[eromano]

Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (check one with "x")

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation
• Other... Please describe:

What is the current behaviour? (You can also link to an open issue here)
use new api siteservice to use memebership

What is the new behaviour?

Does this PR introduce a breaking change? (check one with "x")

• Yes
• No

If this PR contains a breaking change, please describe the impact and migration path for existing applications: ...

Other information:

[codecov-io]

Codecov Report

Merging #5693 into develop will increase coverage by 0.02%.
The diff coverage is 83.33%.

@@             Coverage Diff             @@
##           develop    #5693      +/-   ##
===========================================
+ Coverage    83.64%   83.67%   +0.02%     
===========================================
  Files          908      908              
  Lines        26457    26459       +2     
  Branches      3730     3730              
===========================================
+ Hits         22131    22139       +8     
+ Misses        3211     3203       -8     
- Partials      1115     1117       +2     

Impacted Files	Coverage Δ
lib/core/services/sites.service.ts	58.06% <83.33%> (+2.89%)	⬆️
...lib/process-comments/process-comments.component.ts	71.69% <0.00%> (-1.89%)	⬇️
lib/core/services/translate-loader.service.ts	81.01% <0.00%> (+8.86%)	⬆️

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