Shared: Fix selector for account names with special characters

[rihardsgravis]

Description

Selector get(state.accountInfo, '${payload.accountName}.index') for account names containing special characters that match a valid path e.g. Foo [bar] resolve as undefined.
The selector path should be defined as an array of each path level defined separately.

Fixes #675

Type of change

• Bug fix (a non-breaking change which fixes an issue)

Checklist:

• My code follows the style guidelines for this project
• I have performed a self-review of my own code
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[laumair]

LGTM! 👍 Thank you.