split observation and dimension tests
rename helper function
move sparql templates to separate files
specify observation name in `one_filter` macro
perform trivial 2d query
extract helper function
trim whitespace
extract column pattern macro
inline filteres
get column of common values
rename data_2d to data_xy
Merge branch 'xy-query'

Conflicts:
	scoreboard/visualization/data/cube.py
	scoreboard/visualization/data/tests/sparql_test.py