utilize file filters in webapp test workflows

.github/workflows/test-webapp.yml

@@ -4,8 +4,27 @@ name: ocelot.social webapp test CI
 on: [push]
 
 jobs:
+  files-changed:
+    name: Detect File Changes - Backend
+    runs-on: ubuntu-latest
+    outputs:
+      docker: ${{ steps.changes.outputs.docker }}
+      webbapp: ${{ steps.changes.outputs.webbapp }}
+    steps:
+      - uses: actions/checkout@v3.3.0
+
+      - name: Check for frontend file changes
+        uses: dorny/paths-filter@v2.11.1
+        id: changes
+        with:
+          token: ${{ github.token }}
+          filters: .github/file-filters.yml
+          list-files: shell
+
   prepare:
     name: Prepare
+    if: needs.files-changed.outputs.webbapp
+    needs: files-changed
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
@@ -18,8 +37,9 @@ jobs:
           
   build_test_webapp:
     name: Docker Build Test - WebApp
+    if: needs.files-changed.outputs.docker == 'true' || needs.files-changed.outputs.webbapp
+    needs: [files-changed, prepare]
     runs-on: ubuntu-latest
-    needs: [prepare]
     steps:
       - name: Checkout code
         uses: actions/checkout@v3
@@ -37,6 +57,8 @@ jobs:
 
   lint_webapp:
     name: Lint webapp
+    if: needs.files-changed.outputs.webbapp
+    needs: files-changed
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
@@ -47,8 +69,9 @@ jobs:
 
   unit_test_webapp:
     name: Unit tests - webapp
+    if: needs.files-changed.outputs.docker == 'true' || needs.files-changed.outputs.webbapp
+    needs: [files-changed, build_test_webapp]
     runs-on: ubuntu-latest
-    needs: [build_test_webapp]
     permissions: 
       checks: write
     steps: