Fix bug where the month in which a min date or max date exist are not reachable if the current date is less than or greater than min/max date respectively

[roypearce]

• Adds some tsdoc style documentation to a few methods
• Fixes typescript issues
• Adds stories/tests for the issue with the min and max date causing the month in which those dates occur to be unreachable depending on the actively focused date
• Refactored some tests to be able to be run in isolation, a future Cypress upgrade is going to require this of all tests