lint: minor code clean to nwss

[dshemetov]

Description

Was easier to just make a bunch of changes than to make review comments. It's mostly just code style lints that I preferred, happy to revert some pieces if you disagree. The actual important parts of the code seemed fine to me.

Changelog

• Turn type_dict and type_dict_metric into global constants, remove constructor function
• Remove a few simple functions
• Change the schema change error message, inline the message
• Add logger statement when df_concentration or df_metric contain columns not in TYPE_DICT or TYPE_DICT_METRIC

Fixes

To be merged into #1946

[dsweber2]

Thanks for the suggestions. I think in the future it may just be better to push directly to the branch, since now I have enough suggestions that I could just as readily do a PR on this PR on the base PR, which seems... silly.

[dsweber2]

I'd rather not clutter this function with repeated text when the contents of the warning don't really matter for this function. Definitely should be a KeyError though