Update and audit existing project dependencies for Symfony/Flex.

- Converted all non-flex bundles with available bundles into Symfony/Flex.
- Updated namespaces to more closely match Symfony.
- Removed unnecessary dependencies and recipes.
- Executed Symfony/Flex recipes to create default configs.
- Improved composer.json scripts.

config/packages/cache.yaml

@@ -1,19 +1,19 @@
 framework:
-    cache:
-        # Unique name of your app: used to compute stable namespaces for cache keys.
-        #prefix_seed: your_vendor_name/app_name
+  cache:
+  # Unique name of your app: used to compute stable namespaces for cache keys.
+  #prefix_seed: your_vendor_name/app_name
 
-        # The "app" cache stores to the filesystem by default.
-        # The data in this cache should persist between deploys.
-        # Other options include:
+  # The "app" cache stores to the filesystem by default.
+  # The data in this cache should persist between deploys.
+  # Other options include:
 
-        # Redis
-        #app: cache.adapter.redis
-        #default_redis_provider: redis://localhost
+  # Redis
+  #app: cache.adapter.redis
+  #default_redis_provider: redis://localhost
 
-        # APCu (not recommended with heavy random-write workloads as memory fragmentation can cause perf issues)
-        #app: cache.adapter.apcu
+  # APCu (not recommended with heavy random-write workloads as memory fragmentation can cause perf issues)
+  #app: cache.adapter.apcu
 
-        # Namespaced pools use the above "app" backend by default
-        #pools:
-            #my.dedicated.cache: null
+  # Namespaced pools use the above "app" backend by default
+  #pools:
+  #my.dedicated.cache: null