👌 IMPROVE: Ensure QueryBuilder is passed Backend

[chrisjsewell]

This PR ensures core code always calls QueryBuilder with a specific Backend, as opposed to assuming the loaded Backend.
This will allow for muliple backends to be used at the same time (for example aiida archives), for features including graph traversal and visualisation.

[codecov]

Codecov Report

Merging #5186 (893d275) into develop (d585d14) will increase coverage by 0.01%.
The diff coverage is 93.94%.

@@             Coverage Diff             @@
##           develop    #5186      +/-   ##
===========================================
+ Coverage    81.01%   81.01%   +0.01%     
===========================================
  Files          535      535              
  Lines        37376    37392      +16     
===========================================
+ Hits         30275    30289      +14     
- Misses        7101     7103       +2     

Flag	Coverage Δ
django	75.82% <90.91%> (+0.03%)	⬆️
sqlalchemy	74.94% <90.91%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
aiida/tools/graph/age_entities.py	82.82% <ø> (+0.65%)	⬆️
aiida/tools/graph/deletions.py	76.75% <75.00%> (ø)
aiida/cmdline/utils/common.py	68.85% <80.00%> (-0.02%)	⬇️
aiida/tools/graph/graph_traversers.py	87.94% <83.34%> (-0.66%)	⬇️
aiida/tools/visualization/graph.py	82.70% <91.67%> (+0.14%)	⬆️
aiida/orm/implementation/django/comments.py	95.95% <100.00%> (ø)
aiida/orm/implementation/django/logs.py	96.16% <100.00%> (ø)
aiida/orm/implementation/sqlalchemy/comments.py	94.67% <100.00%> (ø)
aiida/orm/implementation/sqlalchemy/logs.py	94.74% <100.00%> (ø)
aiida/orm/nodes/data/array/bands.py	77.46% <100.00%> (ø)
... and 9 more

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[sphuber]

As discussed prior online, we might want to move to the concept of passing a Profile instance around instead of Backend as the profile concept is more intuitive to a user compared to the backend. However, this required some more discussion and we did more or less agree that having the possibility to pass one of the two explicitly for the querybuilder is necessary, so we are going to merge this PR as is. Thanks @chrisjsewell