Fix build and runtime issues

- Fix Quarkus BOM groupId (io.quarkus:quarkus-bom) and version (3.37.1)
- Fix artifact names: quarkus-resteasy, quarkus-resteasy-qute, quarkus-resteasy-client
- Add UserAgentFilter for MusicBrainz API compliance
- Fix @RestClient qualifier on MB client injection points
- Fix Qute template section names: {#insert}{/insert}, {#else} not {:else}
- Fix template injection with @Location annotation
- Remove unused imports
- Fix RSS feed builder to use Synd API

pom.xml

@@ -45,7 +45,7 @@
     <!-- REST Client -->
     <dependency>
       <groupId>io.quarkus</groupId>
-      <artifactId>quarkus-rest-client</artifactId>
+      <artifactId>quarkus-resteasy-client</artifactId>
     </dependency>
 
     <!-- CDI -->
@@ -75,7 +75,7 @@
     </dependency>
     <dependency>
       <groupId>io.quarkus</groupId>
-      <artifactId>quarkus-rest-client-jackson</artifactId>
+      <artifactId>quarkus-resteasy-client-jackson</artifactId>
     </dependency>
 
     <!-- Test -->