Review new deploymentMode options and (if decided) implement support for them

This section was added to values.yaml as part of the #102 (closed) renovate:

# There are 3 options:
# - SingleBinary: Loki is deployed as a single binary, useful for small installs typically without HA, up to a few tens of GB/day.
# - SimpleScalable: Loki is deployed as 3 targets: read, write, and backend. Useful for medium installs easier to manage than distributed, up to a about 1TB/day.
# - Distributed: Loki is deployed as individual microservices. The most complicated but most capable, useful for large installs, typically over 1TB/day.
# There are also 2 additional modes used for migrating between deployment modes:
# - SingleBinary<->SimpleScalable: Migrate from SingleBinary to SimpleScalable (or vice versa)
# - SimpleScalable<->Distributed: Migrate from SimpleScalable to Distributed (or vice versa)
# Note: SimpleScalable and Distributed REQUIRE the use of object storage.
deploymentMode: SingleBinary

The BB umbrella chart has options for monolith and scalable that translate to SingleBinary and SimpleScalable, but the new Distributed option and the various transition options are not supported within the BB umbrella chart.

This ticket is to gather consensus on what new deployment modes, if any, should be supported and then to implement that support.