Datar

- Add extras in pyproject.toml

**Full Changelog**: https://github.com/pwwang/datar-pandas/compare/0.5.1...0.5.2

- Dismiss ast warning for if_else.
- Make scipy and wcwidth optional deps
- Set seed in tests
- Dismiss warnings of fillna with method for pandas2.1

**Full Changelog**: https://github.com/pwwang/datar-pandas/compare/0.5.0...0.5.1

- ⬆️ Bump datar to 0.15
- ⬆️ Support pandas v2
- datar 0.14 & datar-pandas 0.4 will be last versions to support pandas v1

**Full Changelog**: https://github.com/pwwang/datar-pandas/compare/0.4.0...0.5.0

- Adopt `varname` `v0.8.0`
- Add `base.make_names()` and `base.make_unique()`

- Adopt `pipda` `0.4.5`
- Make dataset names case-insensitive;
- Add datasets: `ToothGrowth`, `economics`, `economics_long`, `faithful`, `faithfuld`, `luv_colours`, `midwest`, `mpg`, `msleep`, `presidential`, `seals`, and `txhousing`
- Add `base.complete_cases()`
- Change `datasets.all_datasets()` to `datasets.list_datasets()`
- Make sure `assume_all_piping` mode works internally: close 45

- Adopt `pipda` 0.4.4
- Add `varname` to dependency to close 30
- Rename `datar.datar_versions` to `datar.get_versions`
- Port a set of functions from r-base, incluing:
- `prod`, `sign`, `signif`, `trunc`, `exp`, `log`, `log2`, `log10`, `log1p`,
- `is_finite`, `is_infinite`, `is_nan`,
- `match`,
- `startswith`, `endswith`, `strtoi`, `chartr`, `tolower`, `toupper`,
- `max_col`