TT-12740 support for jwe tokens in OIDC

[sredxny]

Description

Added support for JWE in OIDC, just need to enable it at profile level and specify where is the cert file located (the cert contains the private key to decrypt the token)

Related Issue

TT-12740

Motivation and Context

How This Has Been Tested

• Running an instance of Keycloak that supports JWE
• Run tyk dashboard and tyk identity broker
• Created an OIDC client in keycloak, load the key and enabled Encrypting of token
• Created a TIB profile like:

  "ID": "keycloak",
  "OrgID": "my-org-id",
  "ActionType": "GenerateOrLoginUserProfile",
  "Type": "redirect",
  "ProviderName": "SocialProvider",
  "ProviderConfig": {
    "CallbackBaseURL": "http://localhost:3010",
    "FailureRedirect": "http://tyk-dashboard:3000/?fail=true",
    "UseProviders": [
      {
        "DiscoverURL": "http://localhost:8080/realms/tyk/.well-known/openid-configuration",
        "Key": "client-id-key",
        "Name": "openid-connect",
        "Scopes": [
          "openid",
          "email"
        ],
        "Secret": "s3cr3t"
      }
    ],
    "JWE": {
      "Enabled": true,
      "Private_key_location": "/location/of/my/combined_cert_and_key.pem",
    }
  },
  "IdentityHandlerConfig": {
    "DashboardCredential": "my-s3cr3t"
  },
  "ReturnURL": "http://tyk-dashboard:3000/tap",
}

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Refactoring or add test (improvements in base code or adds test coverage to functionality)

Checklist

• Make sure you are requesting to pull a topic/feature/bugfix branch (right side). If pulling from your own
  fork, don't request your master!
• Make sure you are making a pull request against the master branch (left side). Also, you should start
  your branch off our latest master.
• My change requires a change to the documentation.
  • If you've changed APIs, describe what needs to be updated in the documentation.
  • If new config option added, ensure that it can be set via ENV variable
• I have updated the documentation accordingly.
• Modules and vendor dependencies have been updated; run go mod tidy && go mod vendor
• When updating library version must provide reason/explanation for this update.
• I have added tests to cover my changes.
• All new and existing tests passed.
• Check your code additions will not fail linting checks:
  • go fmt -s
  • go vet

[sonarcloud]

Quality Gate failed

Failed conditions
73.0% Coverage on New Code (required ≥ 80%)

See analysis details on SonarCloud