feat: Add tx encode and decode endpoints (#13789) (#13868)

* add grpc endpoint for encoding proto tx's

(cherry picked from commit bcff22a)

Co-authored-by: Likhita Polavarapu <78951027+likhita-809@users.noreply.github.com>

CHANGELOG.md

@@ -58,6 +58,8 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* [13789](https://github.com/cosmos/cosmos-sdk/pull/13789) Add tx `encode` and `decode` endpoints to tx service.
+  > Note: This endpoint will only encode proto messages, Amino encoding is not supported.
 * [#13826](https://github.com/cosmos/cosmos-sdk/pull/13826) Support custom `GasConfig` configuration for applications.
 * [#13619](https://github.com/cosmos/cosmos-sdk/pull/13619) Add new function called LogDeferred to report errors in defers. Use the function in x/bank files.
 * (tools) [#13603](https://github.com/cosmos/cosmos-sdk/pull/13603) Rename cosmovisor package name to `cosmossdk.io/tools/cosmovisor`. The new tool directory contains Cosmos SDK tools.