Fix remix depreciation warnings

[Eakam1007]

Resolves #320

Fixed our remix depreciation warnings following their guide

Changes made

• Updated remix config to use v2 route layout
• Rearranged the entire routes folder to use the new v2 route convention. This moves routes out of folders into just files which are easier to see
• Renamed the layout file _index.tsx to _auth.tsx. This was needed because now the index routes are specified by _index.tsx, and it was not possible to specify the index route's layout as _index.tsx
• Updated remix config to use v2 formMethod. I found no instance of formMethod anywhere so nothing else was changed for this
  (Summary of v1 vs v2: navigation.formMethod === "post"; should now be navigation.formMethod === "POST"; etc)
• Updated remix config to use v2 ErrorBoundry API
• Merged all existing CatchBoundry and ErrorBoundy into one ErrorBoundry for each file with checks to render different error layouts. CatchBoundry no longer exists in v2
• Updated remix config to use v2 meta
• Updated root meta function to return array of objects for meta tags instead of a single object with key value pairs

[humphd]

Discussion on Slack: based on https://remix.run/docs/en/main/file-conventions/route-files-v2#nested-layouts-without-nested-urls, we think we should use _auth.* as our pathless, layout route prefix.

[sfrunza13]

Semantically I think that using _auth makes sense because we have to be authenticated for everything to do with starchart. I like it.

[Eakam1007]

Updated to fix the rest of the depreciation warnings + rebased with main

[humphd]

Thanks for doing the error/catch boundary change too. This looks great.