Add List*Organizations helpers in pkg/accessreview/drivers → Ignore .oauth-credentials.txt

- Add List*Organizations helpers in pkg/accessreview/drivers
- Replace AccessSource picker switches with map dispatch
- Drop dead per-provider connector settings wrappers
- Ignore .oauth-credentials.txt

Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>

.gitignore

@@ -22,3 +22,4 @@ pkg/server/api/*/v1/schema.graphql
 cfg/dev_local.yaml
 cfg/dev.yaml
 .env
+.oauth-credentials.txt