Simplifies the rendering logic around document tabs in the following
ways:
- Merges default tabs with custom tabs in a more predictable way, now
there is only a single array of tabs to iterate over, no more concept of
"custom" tabs vs "default" tabs, there's now just "tabs"
- Deduplicates rendering conditions for all tabs, now any changes to
default tabs would also apply to custom tabs with half the code
- Removes unnecessary `getCustomViews` function, this is a relic of the
past
- Removes unnecessary `getViewConfig` function, this is a relic of the
past
- Removes unused `references`, `relationships`, and `version` key
placeholders, these are relics of the past
- Prevents tab conditions from running twice unnecessarily
- Other misc. cleanup like unnecessarily casting the tab conditions
result to a boolean, etc.
53835f2620