[c++] Create specialized templates for `SOMAArray` casting functions

[nguyenv]

Issue and/or context:

https://github.com/single-cell-data/TileDB-SOMA/pull/2975

This is the second of multiple PRs that will be split out from above

Changes:

This is just code reorganization for cleaning up switch-case statements. Create specialized templates for types that need special handling when casting into write buffers. For strings, we need to deal with different size offset buffers depending on whether the user passed in large_string or regular string. For Boolean, we need to convert from Arrow (bit) to TileDB (uint8_t) representation.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 89.87%. Comparing base (7039921) to head (c5fe5aa). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2982 +/- ## ========================================== + Coverage 89.73% 89.87% +0.14% ========================================== Files 39 39 Lines 4080 4080 ========================================== + Hits 3661 3667 +6 + Misses 419 413 -6 ``` | [Flag](https://app.codecov.io/gh/single-cell-data/TileDB-SOMA/pull/2982/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=single-cell-data) | Coverage Δ | | |---|---|---| | [python](https://app.codecov.io/gh/single-cell-data/TileDB-SOMA/pull/2982/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=single-cell-data) | `89.87% <ø> (+0.14%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=single-cell-data#carryforward-flags-in-the-pull-request-comment) to find out more. | [Components](https://app.codecov.io/gh/single-cell-data/TileDB-SOMA/pull/2982/components?src=pr&el=components&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=single-cell-data) | Coverage Δ | | |---|---|---| | [python_api](https://app.codecov.io/gh/single-cell-data/TileDB-SOMA/pull/2982/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=single-cell-data) | `89.87% <ø> (+0.14%)` | :arrow_up: | | [libtiledbsoma](https://app.codecov.io/gh/single-cell-data/TileDB-SOMA/pull/2982/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=single-cell-data) | `∅ <ø> (∅)` | |