fix: make sure wallet scope does not insert accounts (#5374)

## Explanation

This pull request fixes [this
issue](MetaMask/MetaMask-planning#4263).

We appear to be adding an `account` to the wallet scope

Resulting in this failing
[CI](https://app.circleci.com/pipelines/github/MetaMask/metamask-extension/125517/workflows/abdfdb4f-da74-4cc2-9c2f-cf001817f358/jobs/4559282)
for our [Multichain Flask
PR](MetaMask/metamask-extension#27782)

we should add it to the `wallet:eip155` scope (as currently done), but
not just `wallet`.

The fix involves refactoring [core](https://github.com/MetaMask/core)
Multichain package so that creating the `scopeObjects` for each entry,
we make sure that in `wallet` scope string, the accounts property is not
populated.

<!--
Thanks for your contribution! Take a moment to answer these questions so
that reviewers have the information they need to properly understand
your changes:

* What is the current state of things and why does it need to change?
* What is the solution your changes offer and how does it work?
* Are there any changes whose purpose might not obvious to those
unfamiliar with the domain?
* If your primary goal was to update one package but you found you had
to update another one along the way, why did you do so?
* If you had to upgrade a dependency, why did you do so?
-->

## References

<!--
Are there any issues that this pull request is tied to?
Are there other links that reviewers should consult to understand these
changes better?
Are there client or consumer pull requests to adopt any breaking
changes?

For example:

* Fixes #12345
* Related to #67890
-->

## Changelog

<!--
If you're making any consumer-facing changes, list those changes here as
if you were updating a changelog, using the template below as a guide.

(CATEGORY is one of BREAKING, ADDED, CHANGED, DEPRECATED, REMOVED, or
FIXED. For security-related issues, follow the Security Advisory
process.)

Please take care to name the exact pieces of the API you've added or
changed (e.g. types, interfaces, functions, or methods).

If there are any breaking changes, make sure to offer a solution for
consumers to follow once they upgrade to the changes.

Finally, if you're only making changes to development scripts or tests,
you may replace the template below with "None".
-->

### `@metamask/package-a`

- **<CATEGORY>**: Your change here
- **<CATEGORY>**: Your change here

### `@metamask/package-b`

- **<CATEGORY>**: Your change here
- **<CATEGORY>**: Your change here

## Checklist

- [ ] I've updated the test suite for new or updated code as appropriate
- [ ] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [ ] I've highlighted breaking changes using the "BREAKING" category
above as appropriate
- [ ] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

packages/multichain/src/adapters/caip-permission-adapter-eth-accounts.test.ts

@@ -148,11 +148,7 @@ describe('CAIP-25 eth_accounts adapters', () => {
             ],
           },
           wallet: {
-            accounts: [
-              'wallet:eip155:0x1',
-              'wallet:eip155:0x2',
-              'wallet:eip155:0x3',
-            ],
+            accounts: [],
           },
         },
         isMultichainOrigin: false,

packages/multichain/src/adapters/caip-permission-adapter-eth-accounts.ts

@@ -93,11 +93,7 @@ const setEthAccountsForScopesObject = (
     }
 
     let caipAccounts: CaipAccountId[] = [];
-    if (isWalletNamespace) {
-      caipAccounts = accounts.map<CaipAccountId>(
-        (account) => `${KnownWalletScopeString.Eip155}:${account}`,
-      );
-    } else if (namespace && reference) {
+    if (namespace && reference) {
       caipAccounts = accounts.map<CaipAccountId>(
         (account) => `${namespace}:${reference}:${account}`,
       );