Allow quota buckets to be specified in flagd experiment config (#10753)

This PR allows for an easier application of quota buckets using the
flagd config, which is evaluated at runtime. When the context of a
request matches the config, the quota manager will attempt to create a
new quota bucket and store it. If this group+namespace already has a
matching bucket, the bucket creation will be skipped and the existing
bucket will be used. Quota manager refresh or a restart will clear the
buckets, and enable fresh loading from `flagd` for existing buckets, new
buckets will be added automatically.

Author: tyler-french

enterprise/server/quota/BUILD

@@ -34,15 +34,19 @@ go_test(
     deps = [
         "//enterprise/server/backends/authdb",
         "//enterprise/server/backends/userdb",
+        "//enterprise/server/experiments",
         "//proto:quota_go_proto",
         "//server/environment",
         "//server/tables",
         "//server/testutil/pubsub",
+        "//server/testutil/testauth",
         "//server/testutil/testenv",
         "//server/util/db",
         "//server/util/query_builder",
         "@com_github_google_go_cmp//cmp",
         "@com_github_google_go_cmp//cmp/cmpopts",
+        "@com_github_open_feature_go_sdk//openfeature",
+        "@com_github_open_feature_go_sdk//openfeature/memprovider",
         "@com_github_stretchr_testify//assert",
         "@com_github_stretchr_testify//require",
         "@org_golang_google_protobuf//testing/protocmp",