Helm: Allow configuring HA mode for placement separately from global.ha.enabled

[ItalyPaleAle]

For all control plane services except Placement, it's possible to set a replicaCount (for example, dapr_operator.replicaCount) regardless of whether HA mode is enabled for the control plane (global.ha.enabled).

Placement is the only service where insofar it's not possible to enable HA mode without setting global.ha.enabled. This is a problem because it doesn't allow controlling the number of replicas for each control plane service.

This PR adds the option dapr_placement.ha which if set to true, makes Placement deployed in HA mode (with exactly 3 replicas), even if global.ha.enabled is false.

[codecov]

Codecov Report

Merging #6518 (a2526b0) into master (8a995de) will decrease coverage by 0.09%.
The diff coverage is n/a.

❗ Current head a2526b0 differs from pull request most recent head 367bbe9. Consider uploading reports for the commit 367bbe9 to get more accurate results

@@            Coverage Diff             @@
##           master    #6518      +/-   ##
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- Coverage   65.84%   65.76%   -0.09%     
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  Files         198      197       -1     
  Lines       19168    19119      -49     
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- Hits        12621    12573      -48     
+ Misses       5533     5530       -3     
- Partials     1014     1016       +2     

see 8 files with indirect coverage changes