UI issues with Bootstrap 5

[gjvoosten]

Remaining items from #3698:

• Font sizes got bigger throughout the application.
• BlueprintsJS 'core' library could be omitted (with the possible exception of icons). [current React-Bootstrap library lacks Date&Time picker component].
• React-Bootstrap offers similar functionality to some extra libraries that we use; we may want to replace those libraries with standard bootstrap.
• Text in custom field textarea's is vertically aligned in the middle, and newlines can no longer be entered (it looks like those textarea's are rendered not as a textarea but as a regular text input field).
• The modal triggered by ANET Link button inside RichTextEditor falls behind the modal that RichTextEditor is placed in. See notes section in show pages (there might be other places).
• AdvancedSingleSelect components inside AdvancedSearch remain inside of the search box when opened.
• Badges in the CompactRowReportWorkflow don't have enough contrast in the font.
• The Remove Item button in e.g. the Edit History dialog is too far up.
• The ReportStateFilter (e.g. advanced search on Insights with only the state as a filter) overlaps the remove button.
• The checkbox (e.g. advanced search on the Pending Assessments Insight ) is overlapped by the label.
• Date picker components does not display month and year drop-downs when inside of a modal.
• "Changes requested" button in the report workflow pop-up can be wider than the pop-up.
• Assessment modals containing SlateJS editor can be larger so that the toolbar is not wrapped.