mgr/dashboard: Edit should support setting one or more rgw service configuration individually, when multiple rgw service exist

fixes: https://tracker.ceph.com/issues/78332

Before
===
The configuration form had a TypeScript compilation error and could not properly support editing client-specific configurations. The form lacked the ability to:

- Configure different values for specific client entities (e.g., client.rgw.*, client.admin, client.radosgw-gateway)
- No way to Add/remove multiple client entity entries dynamically
- No way to provide autocomplete suggestions for existing client entities

After
===
Users can now edit configuration options individually for any client entity, with a clean UI that supports:

- Generic client entity support: Configure any client.* entity (RGW daemons, admin users, CephFS clients, etc.)
- Autocomplete with custom values: Select from existing client entities or enter custom ones (e.g., client.rgw.my-daemon, client.admin)
- Dynamic entry management: Add/remove multiple client configuration entries

Signed-off-by: Naman Munet <naman.munet@ibm.com>