refactor(group): move ValidateBasic logic to msgServer

[julienrbrt]

Description

Closes: #15648

This PR ended up refactoring and fixing group CLI tests and deduplicating group e2e tests (#15785 (comment)).

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[tac0turtle]

utACK

[likhita-809]

looks like e2e tests are failing. Can you fix them @julienrbrt

[julienrbrt]

looks like e2e tests are failing. Can you fix them @julienrbrt

Yes, deduplicating them 👍🏾

[julienrbrt]

So, learning from this deep dive in testing (cli and e2e):

• Our tx e2e tests are duplicating our message server tests and cli tests and those should be removed, these e2e tests might end up just being e2e query tests after the deduplication.
• Many CLI tests (x/**/client/cli/*_test.go) in the SDK are actually testing nothing, they are not executing the command (!!!), this is fixed for group here, but we need to basically look at all those tests in the SDK
• Our message server tests are pretty good