feat: update proto and remove create_if_not_exists

[evenyag]

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What's changed and what's your intention?

This PR updates proto and removes create_if_not_exists from RegionCreateRequest.

Creating a region needs to be idempotent so create_if_not_exists is always true, we don't need a flag for this.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.

Refer to a related PR or issue link (optional)

[codecov]

Codecov Report

Merging #2467 (7e73530) into develop (6306aea) will decrease coverage by 0.37%.
Report is 3 commits behind head on develop.
The diff coverage is 0.00%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2467      +/-   ##
===========================================
- Coverage    84.88%   84.51%   -0.37%     
===========================================
  Files          726      725       -1     
  Lines       115028   115044      +16     
===========================================
- Hits         97638    97232     -406     
- Misses       17390    17812     +422