Allow flexible_table to update dynamically

This epic is a collection of issues to improve the experience for the use of flexible_table and its derivatives (table_sql and friends).

The end goal is to provide a way for any table in Moodle to support all actions in such a way that the page itself does not reload, merely the content of the table.

The supported actions should include all core table features, including:

• sorting
• showing and hiding of columns
• pagination
• use of the initials bar
• changing the size of the page
• filtering of the table
• resetting any current table preferences