refactor: rename commands to match consensus engine name

[julienrbrt]

Description

ref: #14870

• Rename relevant commands to default to comet. Alias are created to keep backwards compatibility.
• Rename tmservice -> cmtservice. The gRPC endpoints are (for now) remaining unchanged.
• Rename some functions from *Tm* to *Cmt* and alias them for backwards compatibility.
• Functions are under testutil folder are not aliased.

I believe no more renaming is required after this PR. Only docs update.

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[alexanderbez]

small nit: would prefer if all uses of cometbft in strings/code would be replaced with CometBFT :)

[tac0turtle]

Utack