fix: eagerly emit chainChanged events when receiving a successful response from switchChain calls rather than wait for chainChanged event

[adonesky1]

Explanation

Adds an eager call of onChainChanged on connect-evm layer when a switchChain call is successful in order to ensure that the provider's selectedChainId is updated even if the subsequent chainChanged event notification is not received for some reason.

References

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 communicated my changes to consumers by updating changelogs for packages I've changed, highlighting breaking changes as necessary
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes