deposit: refactor section config in RDMDepositForm

* added anchor ids, made form overridable 
* added section path in config 
* added styling for error messages 
* added severity checks config 
* added css for accordion labels 

Co-authored-by: Fatimah Zulfiqar <[email protected]>
Co-authored-by: Carlin Mackenzie <[email protected]>

Author: carlinmack