Cookie chunking support

[tusharpandey13]

Changes

This PR changes the cookie store/retrieve strategy to use cookie chunking on the session cookie.
Also fixed some warnings in some test files.

Write behaviour

• When the session size is larger than 3500 bytes, it will be saved as multiple chunks, delimited by __index.
• Else, a single __session cookie is stored.

Read behaviour

Read bhaviour is backwards compatible with v4.X.X and v3.X.X versions

Testing

PASSING

Test Files  10 passed (10)
      Tests  157 passed (157)
   Start at  17:11:08
   Duration  600ms (transform 249ms, setup 0ms, collect 852ms, tests 203ms, environment 1ms, prepare 462ms)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 98.05825% with 2 lines in your changes missing coverage. Please review.

Project coverage is 77.54%. Comparing base (9f2e29d) to head (c1f3f40).

Files with missing lines	Patch %	Lines
src/server/cookies.ts	97.67%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1975      +/-   ##
==========================================
+ Coverage   76.16%   77.54%   +1.38%     
==========================================
  Files          21       21              
  Lines        1523     1608      +85     
  Branches      242      259      +17     
==========================================
+ Hits         1160     1247      +87     
+ Misses        356      354       -2     
  Partials        7        7              

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