[ICS24] Discard `Default` impl for `ClientId` and move away from `tm_client_type` in unit tests

[Farhad-Shabani]

Problem Statement

Part of #373

Since ClientId serves a wider range of chains, it does not make sense to have a default value. As such, we should also get our unit tests client-indifference and discard tm_client_type calls

[plafer]

Note that our current unit tests have no proof verifications, so even having different client names wouldn't catch bugs like #551. For now, I made sure that our integration tests use different client names.

still a good improvement to have though in the long term.

[Farhad-Shabani]

Definitely. This one caught my eye again while fixing tests for #531.
Unit tests mainly use the MockCotext but having tm_client_type imported, we circumvent the mock in some places