Remove duplicate information from different RD streams

For historical reasons, some hlt2 and spruce lines have identical configurations and duplicate in different streams.

Spruce lines could be useful if the full information is persisted and other information (FT, isolation) are to be processed offline. If this information is meant to be saved online, the spruce lines become a duplicate of work with an impact on the BW. In that case, removing the spruce lines from RD would be ideal.

The following table collects information about HLT2 and spruce lines covering the same channel.

line	proponent	Can the spruce lines be removed?
b_to_multilepton	@tmombach	No, the idea is that these are inclusive B->4body to which you can then add an arbitrary number of particles in the sprucing. That's different to the HLT2 lines
b_to_staux	@htilquin
b_to_xtaul	@tfulghes	YES
b_to_xgamma_exclusive	@isanders	NOT for the moment
b_to_xll	@rmwillia
b_to_ll	@tmombach	NOT for the moment
b_to_kstarmumu	@rmurta ?	this is a hlt2 line, need to check overlap with b_to_xll
b_to_hemu_control_modes	Alexander Battig?	this is a hlt2 line, need to check overlap with b_to_xll

Is the isolation intended to be implemented in the HLT2 or in Spruce line?

Feel free to add comments to the table or comment the issue to open discussion

cc: @mramospe, @matzeni, @htilquin, @alobosal