Proto/Michelson: deprecate timelock types (Follow-up from "Proto/Michelson: Deprecate OPEN_CHEST instruction.")

The following discussion from !6260 (merged) should be addressed:

• @mbouaziz started a discussion: (+2 comments)

  @paracetamolo Do you think we should also prevent people to use the two types chest and chest_key?

  They can't do nothing interesting with them without OPEN_CHEST though if you think the format of the values of those types or even those types may change then it would make sense to deprecate them too

We have deprecated timelock opcode/instruction but should for completeness sake also deprecate types to avoid new contracts being deployed using those types. Even if unlikely.