[PM-129] Refactor email forwarding providers to remove filtering for self-hosted

[gbubemismith]

Type of change

- [ ] Bug fix
- [ ] New feature development
- [X] Tech debt (refactoring, code cleanup, dependency upgrades, etc)
- [ ] Build/deploy pipeline (DevOps)
- [ ] Other

Objective

Modify

This PR updates the Generator Component in apps/web/src/app/tools/generator.component.ts to use a new EmailForwarder model that includes a validForSelfHosted property. This property filters email forwarders based on whether they are valid for self-hosted instances.

Code changes

• libs/common/src/models/domain/email-forwarder-options.ts: Created a EmailForwarderOptions model to include properties that can be used to filter email forwarders.
• libs/angular/src/components/generator.component.ts Updated the forwardOptions variable to use the EmailForwarderOptions model and introduced the validForSelfHosted which can be used to filter the email forwarders.
• apps/web/src/app/tools/generator.component.ts Filtered the forwardOptions list based to allow email forwarders valid for self-hosted instances.

Screenshots

Before you submit

• Please add unit tests where it makes sense to do so (encouraged but not required)
• If this change requires a documentation update - notify the documentation team
• If this change has particular deployment requirements - notify the DevOps team
• Ensure that all UI additions follow WCAG AA requirements

[differsthecat]

Nice work!