Ability to find a member by its username or email

[grananda]

Summary

Finding an organization's member becomes a cumbersome task since the endpoint does not allow for a filter param. This issue suggests the incorporation of a filter param into the endpoint to prevent filtering by looping the results.

Intended outcome

The outcome should return a SINGLE member with the exact search member match

How will it work

api().findOrganizationMember(Long orgId, String user)

It is important for the search to be exact to prevent multiple results to be returned. This is relevant when intending to delete a user1 where a user11 exists.