[MM-56089] Multi language support for captions

[streamer45]

Summary

Adding multi language support to generated captions. The client should now expect a captions: Caption[] field in the recording post props. Tested this in three languages (english, spanish, italian) :)

Ticket Link

https://mattermost.atlassian.net/browse/MM-56089

[codecov-commenter]

Codecov Report

Attention: 4 lines in your changes are missing coverage. Please review.

Comparison is base (3957bea) 5.96% compared to head (e2af8d6) 5.90%.

Files	Patch %	Lines
server/bot_api.go	0.00%	4 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##            main    #586      +/-   ##
========================================
- Coverage   5.96%   5.90%   -0.06%     
========================================
  Files         26      26              
  Lines       5181    5181              
========================================
- Hits         309     306       -3     
- Misses      4848    4850       +2     
- Partials      24      25       +1     

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[streamer45]

Need to update the transcriber for e2e to pass.

[cpoile]

Thank you!