speedup get_source with lookupdict

[JoranAngevaare]

What is the problem / what does the code in this PR do

Speedup #590 with ~40x. We did a lot of checks twice since we went all the way to the lowest dependency for each of the dependencies. This means that e.g. if you have a plugin depending on records_a and records_b which both depend on raw_records you would check raw_records twice.

Rather than using a set, we can also use a lookup dict to keep track of what we have seen. This speeds up the function by ~40x.

Additional benefits

• Allow multiple targets st.get_source('029000', ('cuts_basic', 'event_info'))
• Fix getting dependencies from CutMerger plugins (depends_on as class property)
• Informative function stored_dependencies

Example 1

What sources do we need to start for making 'cuts_basic' and 'event_info':

st = cutax.xenonnt_v5()
st.get_source('029000', ('cuts_basic', 'event_info'))
# gives
{'cut_daq_veto', 'event_basics', 'event_pattern_fit', 'event_positions'}

This means 'cut_daq_veto', 'event_basics', 'event_pattern_fit', 'event_positions' are stored and we can compute 'cuts_basic' and 'event_info' for run '029000'.

Example 2

or get a list of plugins that are needed and stored:

st.stored_dependencies('029000', 'cuts_basic')
# gives
{'cuts_basic': False,
 'cut_daq_veto': True,
 'event_info': False,
 'corrected_areas': False,
 ... }

Meaning we still need to make 'event_info' and 'corrected_areas' to compute cuts_basic whereas we already have cut_daq_veto computed.

[ershockley]

Works very well, thanks @JoranAngevaare! (and sorry for the delay)

[WenzDaniel]

Just a typo I will commit and merge.