feat(cli): Add wallet:encrypt

[rohanjadvani]

Summary

Add CLI command to encrypt the wallet

Testing Plan

❯ f wallet:encrypt
yarn run v1.22.18
$ yarn build && yarn start:js wallet:encrypt
$ tsc -b
? Enter a passphrase to encrypt the wallet: foobar
Encrypting wallet... done

❯ f wallet:encrypt
yarn run v1.22.18
$ yarn build && yarn start:js wallet:encrypt
$ tsc -b
Wallet is already encrypted
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Documentation

Does this change require any updates to the Iron Fish Docs (ex. the RPC API
Reference)? If yes, link a
related documentation pull request for the website.

[x] Yes

Breaking Change

Is this a breaking change? If yes, add notes below on why this is breaking and label it with breaking-change-rpc or breaking-change-sdk.

[ ] Yes