fix: support time selection with selectsRange for showTimeInput

[martijnrusschen]

Fixes #3673 and #4649

• When selectsRange is true with showTimeInput, render two time inputs (one for start date, one for end date)
• Add modifyDateType parameter to handleTimeChange to explicitly specify which date to modify
• Each time input independently updates its corresponding date
• Add 7 new tests for showTimeInput with selectsRange functionality

Changes:

• src/index.tsx: Updated handleTimeChange to accept modifyDateType param
• src/calendar.tsx: Updated renderInputTimeSection to render two inputs
• src/test/datepicker_test.test.tsx: Added tests for new functionality

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.23%. Comparing base (a9517e4) to head (ac15422).
⚠️ Report is 91 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6079      +/-   ##
==========================================
+ Coverage   99.14%   99.23%   +0.08%     
==========================================
  Files          30       30              
  Lines        3612     3644      +32     
  Branches     1548     1571      +23     
==========================================
+ Hits         3581     3616      +35     
+ Misses         29       27       -2     
+ Partials        2        1       -1     

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