fix: improve custom_properties hashing to resolve false / missing diffs

[PavelSusloparov]

Issue:
Terraform does not detect changes during the custom_properties updates.

Solution:
Use field hashing and consistent hashing.

What changed?

1. Complete field hashing: The hash now includes all fields (key, name, value), not just the key. This ensures Terraform can properly identify when any field changes.
2. Consistent hashing: By using a struct and including all fields, the hash remains consistent even when Terraform's internal TypeSet mechanism calls the function multiple times.
3. Sorted values: Values are now consistently sorted in both directions (write and read), ensuring state consistency.

Wait!

• Have you added comprehensive tests?
• Have you updated relevant data sources as well as resources?
• Have you updated the docs?

Testing

For any changes you make, please ensure your acceptance test conform to the following:

• every single new attribute is tested
• optional attributes revert to null or default values if removed
• attributes that interact interact as expected
• block values behave as expected when reordered
• nested fields on maps or list/set items function as expected. Terraform does not actually enforce most schema attributes on nested items
• each test step for a configuration is followed by a test step where ImportState and ImportStateVerify are set to true. ImportStateVerifyIgnore can be used if we explicitly expect a value to be different when imported, such as in the case of obfuscated values like API keys

LaunchDarkly Employees

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[sloloris]

@PavelSusloparov looks great, thank you for this!!!

[sloloris]

hi @PavelSusloparov, i have triggered a release. your changes should appear in v2.26.2 within a couple of hours (but probably less).