Update groundwater signatures module

[raoulcollenteur]

Short Description

This PR updates the groundwater signatures module, after cross-checking with methods from Haaf and Heudorfer and additional logical checks in interpreting the computed signatures. It also adds a few new signatures.

Checklist before PR can be merged:

• closes issue [Development] Groundwater Signatures in Pastas #370
• is documented
• Format code with Black formatting
• type hints for functions and methods
• tests added / passed
• Example Notebook (for new features)
• Remove output for all notebooks with changes

[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
❌ -0.17% (target: +0.00%)	✅ 77.61%

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (bd511df)	5834	4359	74.72%
Head commit (d453175)	5991 (+157)	4466 (+107)	74.55% (-0.17%)

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#636)	268	208	77.61%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

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[raoulcollenteur]

This one should be good to go now after many, many changes to the code and docs.

Requested changes were made.