add new_constant for Bitmap

[codecov[bot]]

Codecov Report

Attention: 11 lines in your changes are missing coverage. Please review.

Comparison is base (dd80c89) 83.38% compared to head (c94a4dc) 83.36%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1579 +/- ## ========================================== - Coverage 83.38% 83.36% -0.03% ========================================== Files 391 391 Lines 42971 42982 +11 ========================================== - Hits 35833 35831 -2 - Misses 7138 7151 +13 ``` | [Files](https://app.codecov.io/gh/jorgecarleitao/arrow2/pull/1579?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Jorge+Leitao) | Coverage Δ | | |---|---|---| | [src/bitmap/immutable.rs](https://app.codecov.io/gh/jorgecarleitao/arrow2/pull/1579?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Jorge+Leitao#diff-c3JjL2JpdG1hcC9pbW11dGFibGUucnM=) | `81.97% <0.00%> (-4.07%)` | :arrow_down: | ... and [2 files with indirect coverage changes](https://app.codecov.io/gh/jorgecarleitao/arrow2/pull/1579/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Jorge+Leitao)

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[sundy-li]

how about naming new_constant