PMM-13794: Add HAService integration to server initialization

[BupycHuk]

PMM-13794

Link to the Feature Build: SUBMODULES-3855

If this PR adds or removes or alters one or more API endpoints, please review and add or update the relevant API documents as well:

• API Docs updated

If this PR is related to some other PRs in this or other repositories, please provide links to those PRs:

• Links to related pull requests (optional).

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 43.67%. Comparing base (2caec1e) to head (0b777de).
Report is 16 commits behind head on v3.

Files with missing lines	Patch %	Lines
managed/cmd/pmm-managed/main.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##               v3    #3686      +/-   ##
==========================================
+ Coverage   43.62%   43.67%   +0.04%     
==========================================
  Files         366      366              
  Lines       44328    44338      +10     
==========================================
+ Hits        19338    19363      +25     
+ Misses      23310    23293      -17     
- Partials     1680     1682       +2     

Flag	Coverage Δ
managed	45.39% <50.00%> (+<0.01%)	⬆️

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