add tests for apkam authorization for sub namespaces

[murali-shris]

Is your feature request related to a problem? Please describe.

Is an apkam enrollment has access to a namespace, then it should be able to access sub namespaces
e.g
if enrollment has access to .buzz, then .contacts.buzz, .notifications.buzz should be allowed

Describe the solution you'd like

write tests to validate the authorization check for sub namespaces

Describe alternatives you've considered

No response

Additional context

No response

[murali-shris]

@gkc @sitaram-kalluri
subnamespace authorization currently works because of this behavior

update:phone.contacts.buzz@alice 1234

In AtKey implementation, phone.contacts is treated as key and buzz as the namespace

in the above scenarion AtKey.fromString('phone.contacts.buzz@ alice').namespace should return buzz or contacts.buzz ?

[gkc]

It should continue to return buzz.

[purnimavenkatasubbu]

Tests has been added in the following branch

[murali-shris]

#2051