Settings: make bank account associations more dynamic, part 1
Settings: Refrase account section intro text
Introduce fct_get_currency_position_format

Returns sprintf-ready string for currency symbol and
value to combine. Used by fct_get_currency_format.

* Fixed float format logic to acknowledge already floats.
Merge fct_get_currency_position_format() into fct_get_currency_positions()
Implement `menu_name` and `name_admin_bar` post type labels

Additionally:
* Correct period/account/record map_meta_cap filters
* Introduce `fct_is_account_period_closed`, `fct_is_record_account_closed` and
  `fct_is_record_period_closed`
Fix editing/deleting record/account/period capabilities

* Removed read/edit/delete_private_* caps. There are no private objects
* Removed record closed status and associated functions
Implement close period action
Better redirect and admin messages when missing open period or open account
First attempt to inherit accounts on create period
Minor fixes and inline documentation in period account inheritance
Minor period account documentation fixes
Fix account meta logic in account inheritance
Prevent records to be added to closed accounts
Light restructuring of object dropdowns

* Introduce fct_{get_}_period_dropdown()
* Order periods by post date
* Keep forced accounts in dropdown when querying records
Reset account dropdown params when querying records in all periods
Fix disabling dropdown options in `Fiscaat_Walker_Dropdown`
Implement secondary account ordering by post date