Use 'fct_ledger_dropdown' for record list table filter

This enables querying for the bare ledger ID instead of having the account ID
in the request url twice.

* 'fct_get_dropdown' facilitates the 'data' arg for setting data-attributes
* Account dropdowns have a data-attribute of 'ledger_id' with their corresponding ledger ID by default
* JS dropdown sync is rewritten to use data-attributes
* Setting up the proper $_REQUEST record query args is now done on the earliest load of the records admin page
* Where appropriate all uses of $_GET are changed to $_REQUEST