fix(date-picker): cleanup date-picker tests, add some FIXME

[yqrashawn]

1. mostly cleanup
2. there's some type error in test files, added some FIXME

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Checklist

• [x] Fix linting errors
• [x] Tests have been added / updated (or snapshots)

[codecov[bot]]

Codecov Report

Merging #81 into date-picker-component will not change coverage. The diff coverage is n/a.

@@                   Coverage Diff                   @@
##           date-picker-component       #81   +/-   ##
=======================================================
  Coverage                 100.00%   100.00%           
=======================================================
  Files                        200       200           
  Lines                       2798      2798           
  Branches                     714       722    +8     
=======================================================
  Hits                        2798      2798           

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[ConfluxBot]

:tada: This PR is included in version 1.0.0-alpha.46 :tada:

The release is available on:

• npm package (@alpha dist-tag)
• GitHub release

Your semantic-release bot :package::rocket:

[ConfluxBot]

:tada: This PR is included in version 1.1.0 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: