Excel import improvements

[luke-quadratic]

Import Excel button gets used quite often - this is a tracking list for improvements to importing Excel sheets from the dashboard.

• [ ] Import formatting
• [ ] Import formulas

Please feel free to edit and add to the list (and please comment any additional features you want as part of this!)

[ddimaria]

We haven't done any formula imports yet. It might be a good PoC to convert a single formula to get a sense of the LOE on doing this en mass.

[davidfig]

We should be able to just import the formulas. Some of them won't work (since we don't support all the excel functions), but it should mostly work.

[ddimaria]

Sadly, the excel import crate we're currently using doesn't parse formatting data. When we start this, I'll look into other tools and/or the effort involved in parsing formatting information in a fork of our current excel import crate.

[luke-quadratic]

duplicate (formulas solved, issue created for formatting #2981