refactor(edr): manual water level contract data shape tests (BDMS-1542) - #1054

This work will be done in a series of stacked PRs and therefore I expect these tests to fail until all of the subsequent PRs get approved and merged into this one.

Why

This PR addresses the following problem / context:

• The shape of the FeatureCollection and CoverageCollection need to be described by tests
• The views upon which the /manual_waterlevels collection depend should be described by tests

How

Implementation summary: the following was changed / added / removed:

• Moved all relevant tests about ogc manual waterlevels to the same testing file
• Added tests describing and validating the data served for both the FeatureCollection and CoverageCollection
• Added tests describing the ogc_manual_waterlevels view

Author Checklist

• Changes are limited to the intended scope.
• Tests were added or updated where appropriate.
• [] Relevant tests and lint checks pass.
• No secrets, credentials, or sensitive data were publicly exposed.
• Documentation was updated where necessary.

Reviewer Checklist

• Use checkboxes here

Notes

Any special considerations, known limitations, risks, workarounds, or follow-up work to note?

• The test tests/test_ogc_field_descriptions.py::test_edr_independent_axis_documents_its_parameters already exists in the branch into which this will be merged. I don't know why it's exists here. So it's in both this PR and the one above it.