Move wallet_*snap methods to Snaps docs

[alexandratran]

Description

Move wallet_snap, wallet_invokeSnap, wallet_getSnaps, and wallet_requestSnap docs to a new reference page in the Snaps docs, "Wallet API for Snaps." Update context and links accordingly.

Also see https://github.com/MetaMask/api-specs/pull/218, which removes these methods from the interactive reference.

Issue(s) fixed

Fixes #1283

Preview

https://docs.metamask.io/1283-move-snaps-methods/snaps/reference/wallet-api-for-snaps/

Checklist

Complete this checklist before merging your PR:

• [x] If this PR contains a major change to the documentation content, I have added an entry to the top of the "What's new?" page.
• [ ] The proposed changes have been reviewed and approved by a member of the documentation team.

[github-actions[bot]]

Preview published: 1283-move-snaps-methods

[github-actions[bot]]

Preview published: 1283-move-snaps-methods

[github-actions[bot]]

Preview published: 1283-move-snaps-methods

[alexandratran]

@Montoya Good catch, fixed along with one other link

[github-actions[bot]]

Preview published: 1283-move-snaps-methods