feat: add service binding resources and data sources

[lechnerc77]

Purpose

• This PR adds the resources and data sources needed for the service bindings in SAP BTP
• It contains the corresponding tests and recorded test fixtures
• documentation is updated

Closes #231 and #235

Does this introduce a breaking change?

[ ] Yes
[X] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[X] Feature
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

How to Test

• Test the code

go test ./...

What to Check

Verify that the following are valid

• Test succeed

Other Information

As a side-effect from recording the fixtures, the provider_test.go was enhanced to remove client IDs and client secrets from the recordings