This commits deperecates GetInstallers, which should be replaced by a paginated counterpart: ListInstallers
A new stream helper `MergeStreamsWithPriority` is added which can be used to resolve
clashing compare keys in two streams.
Towards: gravitational/teleport.e/issues/6759
Changelog: Add paginated API ListInstallers, deprecate GetInstallers
This commits deperecates GetDatabases, which
should be replaced by a paginated counterpart:
ListDatabases
The commit also adds TakeWhile for conditional
iter stream reads.
Towards: gravitational/teleport.e/issues/6759
Changelog: Add paginated API ListDatabases, deprecate GetDatabases