feat: add show_stats_public field

[uds5501]

Fixes #6031

Checklist

• I have read the Contribution & Best practices Guide and my PR follows them.
• My branch is up-to-date with the Upstream development branch.
• The unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

• All the functions created/modified in this PR contain relevant docstrings.

Short description of what this resolves:

Add show_stats_public field for as requested in FE issue

[codecov]

Codecov Report

Merging #6032 into development will increase coverage by <.01%.
The diff coverage is 100%.

@@               Coverage Diff               @@
##           development    #6032      +/-   ##
===============================================
+ Coverage        66.26%   66.27%   +<.01%     
===============================================
  Files              285      285              
  Lines            14007    14010       +3     
===============================================
+ Hits              9282     9285       +3     
  Misses            4725     4725

Impacted Files	Coverage Δ
app/api/schema/events.py	90% <100%> (+0.06%)	⬆️
app/models/event.py	82.06% <100%> (+0.13%)	⬆️

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[kushthedude]

I suggest to make, Default Value: False as in fossasia/open-event-frontend#3112

[kushthedude]

Looks Great!

[iamareebjamal]

Need a better name than this - show_stats_public

[kushthedude]

@uds5501 Change it to ‘show_remaining_tickets ‘

[shreyanshdwivedi]

@uds5501 please refer to fossasia/open-event-frontend#3112 (review)

[uds5501]

@kushthedude @iamareebjamal @shreyanshdwivedi completed the change