Undo the changes introduced in #2332 #2412 and #2483

[romac]

Follow-up to #2710.

The idea is to undo (some of) the changes introduced in the following PRs, to keep the definitions in ibc-relayer-types as canonical as possible, without object safety concerns.

This means that we have to re-introduce the Any[Header,Client,etc.] enums in the relayer-types crate, but perhaps there is a better design to be found.

• Remove all occurences of Any* enums from light-clients #2332
• Object safe Protobuf #2412
• Light client extraction #2483

[adizere]

Seems done, thank you Romain!

[romac]

It's not actually done, but we may want to discuss which parts of this we actually want to revert. Not a priority right now though so let's push it to 1.3.

[romac]

Done in #3671