TMSS-287: added Quantity AbstractChoice model, and used it in ResourceType to annotate each resource type with the correct quantity.

TMSS-287: upon request of the frontend team, added more test data and added some scheduled/blueprinted tasks as well. Use TMSS_UNIT_TESTING envvar to skip expensive example data setup.

TMSS-287: indicate (via environment var) that we are using the TMSSTestEnvironment during unittesting.

Build scheduler standalone

See merge request !183

Resolve TMSS-286

Closes TMSS-286

See merge request !187

TMSS-286: use the RelationalHyperlinkedModelSerializer so we always get both the pk and url, and we get additional _value fields for enums

Resolve TMSS-221

Closes TMSS-221

See merge request !186

TMSS-221: Fix nested url for listing projects in a cycle when cycle name contains a space. Also allow filtering project list by cycle via url parameter.

# Conflicts:
#   Docker/lofar-ci/Dockerfile_ci_sas

Resolve TMSS-241

Closes TMSS-241

See merge request !184

TMSS-241: remove units from resource models (which should always be in SI/base units on the DB level)