[Feature] Add borsh support for `TxKind`

[mablr]

Component

primitives

Describe the feature you would like

This is a followup for #992.

To unlock alloy-rs/alloy#2946 and close alloy-rs/alloy#2803 we need Borsh support for TxKind here.

There may be other relevant types to support. Suggest them if you see any... 😄

I will propose a PR.

Additional context

No response