[FEATURE] Show aliases under data source options when creating detector

[amsiglan]

Is your feature request related to a problem?
When creating detector, the options in the dropdown menu for data sources only shows indices. Though the user can manually add names of aliases, it would be easier if we also show the available aliases in the dropdown menu.

What solution would you like?
We should add aliases to the list as well. Opensearch has a GET API for aliases which can be used for this enhancement.