Replaced `GetOrCreateEndpointCommand` with `ObtainEndpointCommand`
to improve clarity and align with naming conventions. Removed
`GetOrCreateEndpointCommand` and its handler, and introduced
`ObtainEndpointCommand` with equivalent functionality.
Updated `MappingProfile.cs` to map `ObtainEndpointCommand` to
`Endpoint`. Refactored `CreateRecActionCommand.cs` to use the
new `ObtainEndpointCommand` for retrieving or creating `Endpoint`
entities.
These changes ensure consistent naming and maintain the same
behavior while improving code readability.
