feat(docker): add OAUTH_USE_BASIC_AUTH env (#7474)

Makes the last `initOAuth` variable configurable via environment
variables in the swagger-ui docker image.

Co-authored-by: Christopher Giroir <chrisgiroir@improbable.io>
Co-authored-by: Tim Lai <timothy.lai@gmail.com>

docker/configurator/oauth.js

@@ -31,6 +31,10 @@ const oauthBlockSchema = {
     type: "object",
     name: "additionalQueryStringParams"
   },
+  OAUTH_USE_BASIC_AUTH: {
+    type: "boolean",
+    name: "useBasicAuthenticationWithAccessCodeGrant"
+  },
   OAUTH_USE_PKCE: {
     type: "boolean",
     name: "usePkceWithAuthorizationCodeGrant"