test: harmonize RemoteStartTransaction tests across OCPP stacks

test: harmonize RemoteStartTransaction tests across OCPP stacks

OCPP 1.6:
- Remove fabricated TC_0XX_CS codes (no official 1.6 test case spec)
- Reorder tests by category: happy path, input validation, availability,
  transaction state, event listeners

OCPP 2.0:
- Add 2 EVSE availability tests (skip inoperative, all inoperative)
- Add official TC refs where tests match Part 6 spec (TC_F_02_CS,
  TC_F_03_CS, TC_K_37_CS)
- Harmonize FR comment format on new tests