SB: Create e2e SKR test for all new service bindings capabilities

[PK85]

Subtask of the EPIC: #284

AC

• 1) one e2e SKR test calling KEB APis
  • 1.1) SB: Integration Test for Gardener Kubeconfig Expiration #1239, PR#1244
  • 1.2) add GET and DELETE test for TOKEN+REQUEST and GARDENER (they must fail if GET has dummy response, and when DSELETE TOKEN_REQUEST previous kubeconfig must NOT work, and for GARDENER it must still work)
    GET and DELETE in Kyma Binding SKR test #1249
  • 1.3) test validation for expiration_seconds with less than 10 min, and more than 2h. Must fail and check validation message. Add binding expiration tests to SKR tests #1261
  • 1.4) Create 11 bidings, 11th must fail with proper validation message Add SKR test for creating more than 10 bindings #1283
    -[ ] 2) new type of e2e test (could be written in go, special for Mr Wojciech).
    - [ ] 2.1) Setup: We have prepared subacout on staging with Provisioing Service instance and binding,
    - [ ] 2.2) Setup: Kyma entitlement added for example to AWS plan
    - [ ] 2.3) New test, where provisioning API creates Kyma cluster + Service Bindings, we can still use KCP CLI tech users to validate some things, or show why it failed. Use the SB kubeconfig and reach Kyma instance.

[MarekMichali]

Part 2 about provisioning api was moved to #1341