Merge pull request #13570 from backstage/freben-dschwank/user-settings-backend

feat: add user-settings-backend and related frontend store

.changeset/healthy-oranges-fly.md

@@ -0,0 +1,6 @@
+---
+'@backstage/plugin-user-settings-backend': minor
+---
+
+Added new plugin `@backstage/plugin-user-settings-backend` to store user related
+settings in the database.

.changeset/six-apricots-add.md

@@ -0,0 +1,7 @@
+---
+'@backstage/plugin-user-settings': patch
+---
+
+Added a `UserSettingsStorage` implementation of the `StorageApi` for use as
+drop-in replacement for the `WebStorage`, in conjunction with the newly created
+`@backstage/plugin-user-settings-backend`.

.changeset/sixty-apes-wait.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-shortcuts': patch
+---
+
+Ensure that a stable observable is used in the shortcuts API

.changeset/strange-geckos-know.md

@@ -0,0 +1,5 @@
+---
+'@backstage/core-app-api': patch
+---
+
+Clarify that the `WebStorage` observable returns `JsonValue` items.