feat: add confirmation modal pre video call, make style changes local to calling modal

[arjita-mitra]

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PR Submission Checklist for internal contributors

• The PR Title

  • Prevent accidental calls in large groups [Web] Confirmation when initiating a call in a large group

• The PR Description

  • As a Wire user, I would like to see a confirmation screen when calling a large group so that I do not disturb a large group of people inadvertently

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References

1. https://wearezeta.atlassian.net/browse/SQSERVICES-1923

[codecov]

Codecov Report

Merging #15182 (d7e805f) into dev (20b50f7) will increase coverage by 0.01%.
The diff coverage is 55.55%.

@@            Coverage Diff             @@
##              dev   #15182      +/-   ##
==========================================
+ Coverage   43.20%   43.21%   +0.01%     
==========================================
  Files         644      644              
  Lines       21656    21659       +3     
  Branches     4959     4961       +2     
==========================================
+ Hits         9357     9361       +4     
+ Misses      11106    11105       -1     
  Partials     1193     1193