[Database Adapter] Fix context with query structure

[marcocapozzoli]

Contexts with the structure below are not working for mapping SQL to MeTTa/Atoms

SQL table_experiment_1 <SELECT grp.uniquename as public_grp__uniquename, grp.name as public_grp__name
FROM grp
JOIN grpmember ON grpmember.grp_id = grp.grp_id
JOIN feature_grpmember ON feature_grpmember.grpmember_id = grpmember.grpmember_id
JOIN feature ON feature.feature_id = feature_grpmember.feature_id
WHERE feature.name = 'Abd-B' AND feature.is_obsolete = 'f';>

SQL gene_expr_1 <select distinct
    feature.name as public_feature__name,
    feature.uniquename as public_feature__uniquename,
    library.uniquename as public_library__uniquename,
    library_featureprop.value as public_library_featureprop__value
from feature
join library_feature on library_feature.feature_id = feature.feature_id
join library on library.library_id = library_feature.library_id
left join library_featureprop on library_featureprop.library_feature_id = library_feature.library_feature_id
where library_featureprop.type_id = '151505' and
library.uniquename in (
'FBlc0003850', 'FBlc0003851', 'FBlc0003852', 'FBlc0003853', 'FBlc0003854', 
'FBlc0003855', 'FBlc0003856', 'FBlc0003857', 'FBlc0003858', 'FBlc0003859', 
'FBlc0003860', 'FBlc0003861', 'FBlc0003862', 'FBlc0003863', 'FBlc0003864', 
'FBlc0003865', 'FBlc0003866', 'FBlc0003867', 'FBlc0003868', 'FBlc0003869', 
'FBlc0003870', 'FBlc0003871', 'FBlc0003872', 'FBlc0003873', 'FBlc0003874');>