[WIP] fix: support format in from_unixtime

[kazuyukitanimura]

Which issue does this PR close?

Closes #.

Rationale for this change

What changes are included in this PR?

How are these changes tested?

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 45.87%. Comparing base (f09f8af) to head (613e3cd).
⚠️ Report is 692 commits behind head on main.

Files with missing lines	Patch %	Lines
...c/main/scala/org/apache/comet/serde/unixtime.scala	0.00%	2 Missing ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##               main    #2769       +/-   ##
=============================================
- Coverage     56.12%   45.87%   -10.25%     
- Complexity      976     1212      +236     
=============================================
  Files           119      164       +45     
  Lines         11743    14004     +2261     
  Branches       2251     2372      +121     
=============================================
- Hits           6591     6425      -166     
- Misses         4012     6538     +2526     
+ Partials       1140     1041       -99     

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[comphead]

nice, this is needed!