DetectorDatabase is now implemented with a translation-invariant key system

[nelimee]

This PR fixes #374 and refactor a little bit DetectorDatabase and its accompanying key data-structure _DetectorDatabaseKey to:

1. be translation free, meaning that now equivalent pairs of subtemplates/plaquettes are mapped to the same database entry.
2. use a simpler hashing method that is fully contained in the database.py (and not spread in the different data-structures used) and only require that Plaquette.name is a valid way of comparing/hashing plaquettes (i.e., the following assertion should hold: "two plaquettes have the same name iff they are equal").

[github-actions]

Package	Line Rate	Complexity	Health
src.tqec	97%	0	✔
src.tqec.circuit	97%	0	✔
src.tqec.circuit.detectors	94%	0	✔
src.tqec.circuit.detectors.match_utils	90%	0	✔
src.tqec.compile	95%	0	✔
src.tqec.compile.detectors	83%	0	✔
src.tqec.compile.specs	82%	0	✔
src.tqec.compile.specs.library	100%	0	✔
src.tqec.computation	84%	0	✔
src.tqec.computation.block_graph	91%	0	✔
src.tqec.gallery	100%	0	✔
src.tqec.noise_models	94%	0	✔
src.tqec.plaquette	90%	0	✔
src.tqec.plaquette.library	100%	0	✔
src.tqec.simulation	0%	0	❌
src.tqec.simulation.plotting	0%	0	❌
src.tqec.templates	89%	0	✔
Summary	91% (3839 / 4205)	0	✔

[github-actions]

🪓 PR closed, deleted preview at https://qchackers.github.io/tqec/pull/376/