feat: readExcel support

[Bidek56]

Initial support for readExcel #331.
fastExcel used, which is the same Excel library as used in the main project.

[Bidek56]

After adding fastexcel crate, nodejs-polars.darwin-arm64.node file size goes from 66Mbs to 79Mbs.
I am hesitant on adding the fastexcel dependency. @universalmind303 what do you think? thx

[universalmind303]

@Bidek56 yeah, that's a pretty big increase! what I would prefer is if there was a way to make it an optional dependency, but that's pretty tricky with napi.

Alternatively, we could do it all on the js side of things. Have the read_excel function in JS create some arrow arrays. Then you can zero copy those into rust.

[Bidek56]

@Bidek56 yeah, that's a pretty big increase! what I would prefer is if there was a way to make it an optional dependency, but that's pretty tricky with napi.

Alternatively, we could do it all on the js side of things. Have the read_excel function in JS create some arrow arrays. Then you can zero copy those into rust.

yes, but the Excel JS packages are either not maintained, like exceljs or SheetJS, which isn’t fully open source.

[Bidek56]

read-excel-file is maintained and popular but I rather use a package which is used by the main repo like fastexcel

[Bidek56]

Closing due to increase in .node file size.