[chore] fix the metadata of extension/xextension/storage (#12398)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description
- add new metadata.yaml file to `extension/xextension/storage` and add
@swiatekm as codeowner there
- remove @swiatekm from metadata.yaml file at `extension/xextension`
- regenerate codeowners

<!-- Issue number if applicable -->
#### Link to tracking issue
Fixes #12382

Author: atoulme

.github/CODEOWNERS

@@ -36,7 +36,8 @@ exporter/otlpexporter/                   @open-telemetry/collector-approvers
 exporter/otlphttpexporter/               @open-telemetry/collector-approvers
 exporter/xexporter/                      @open-telemetry/collector-approvers @mx-psi @dmathieu
 extension/memorylimiterextension/        @open-telemetry/collector-approvers
-extension/xextension/                    @open-telemetry/collector-approvers @swiatekm
+extension/xextension/                    @open-telemetry/collector-approvers
+extension/xextension/storage/            @open-telemetry/collector-approvers @swiatekm
 extension/zpagesextension/               @open-telemetry/collector-approvers
 pdata/                                   @open-telemetry/collector-approvers @BogdanDrutu @dmitryax
 pdata/pprofile/                          @open-telemetry/collector-approvers @mx-psi @dmathieu

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -37,6 +37,7 @@ body:
       - exporter/x
       - extension/memorylimiter
       - extension/x
+      - extension/x/storage
       - extension/zpages
       - pdata
       - pdata/pprofile

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -31,6 +31,7 @@ body:
       - exporter/x
       - extension/memorylimiter
       - extension/x
+      - extension/x/storage
       - extension/zpages
       - pdata
       - pdata/pprofile

.github/ISSUE_TEMPLATE/other.yaml

@@ -30,6 +30,7 @@ body:
       - exporter/x
       - extension/memorylimiter
       - extension/x
+      - extension/x/storage
       - extension/zpages
       - pdata
       - pdata/pprofile

extension/xextension/metadata.yaml

@@ -4,7 +4,5 @@ github_project: open-telemetry/opentelemetry-collector
 status:
   class: extension
   codeowners:
-    active:
-      - swiatekm
   stability:
     development: [profiles]

extension/xextension/storage/metadata.yaml

@@ -0,0 +1,10 @@
+type: xextension
+github_project: open-telemetry/opentelemetry-collector
+
+status:
+  class: extension
+  codeowners:
+    active:
+      - swiatekm
+  stability:
+    development: [profiles]