[CPDNPQ-2317] change validation and do not destroy declarations

[alkesh]

Context

Ticket: https://dfedigital.atlassian.net/browse/CPDNPQ-2317

When there are voided statement items and a voided declaration, it is currently not possible to revert an application to pending.
It raises an error in the admin console:

ActiveRecord::InvalidForeignKey in NpqSeparation::Admin::Applications::RevertToPendingController#create`
PG::ForeignKeyViolation: ERROR: update or delete on table "declarations" violates foreign key constraint "fk_rails_19a5cbebb5" on table "statement_items"
DETAIL: Key (id)=(1278) is still referenced from table "statement_items".

Changes proposed in this pull request

• Change the validation, so that only applications with declaration in revertable states(voided, ineligible, awaiting_clawback, clawed_back) can be reverted to pending
• Do not delete any declarations
• If there are declarations with states submitted, eligible, payable or paid - an error will be shown.
• Previously declarations that were in state submitted were allowed - but this has been removed - the provider will have to void those declarations first if they want the application reverted to pending.

The error you get if the state of the declarations are not revertable is:

[github-actions]

Review app deployed to https://npq-registration-review-2131-web.test.teacherservices.cloud/

[rwrrll]

Could we use Applications::RevertToPending::REVERTABLE_DECLARATION_STATES here?

[rwrrll]

Could we use Applications::RevertToPending::REVERTABLE_DECLARATION_STATES here too?

[rwrrll]

Suggested change

	pending_unremoveable_declarations: There are already declarations for this participant on this course, please ask the provider to void and/or clawback any declarations they have made before attempting to reset the application.
	pending_unremoveable_declarations: There are already declarations for this participant on this course, please ask the provider to void any declarations they have made before attempting to revert the application.

From a provider's perspective, they can only void a declaration. Whether it goes to void or through the clawback states is determined by Declarations::Void#void checking whether money has changed hands, but the provider has no control over that.

Also tiny change for consistent verb revert (could also change i18n key)

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud