chore: move app URL parsing to its own package (#11651)

* chore: move app url parsing to it's own package

cli/testdata/coder_server_--help.golden

@@ -167,7 +167,7 @@ NETWORKING OPTIONS:
       --secure-auth-cookie bool, $CODER_SECURE_AUTH_COOKIE
           Controls if the 'Secure' property is set on browser session cookies.
 
-      --wildcard-access-url url, $CODER_WILDCARD_ACCESS_URL
+      --wildcard-access-url string, $CODER_WILDCARD_ACCESS_URL
           Specifies the wildcard hostname to use for workspace applications in
           the form "*.example.com".
 

cli/testdata/server-config.yaml.golden

@@ -4,8 +4,8 @@ networking:
   accessURL:
   # Specifies the wildcard hostname to use for workspace applications in the form
   # "*.example.com".
-  # (default: <unset>, type: url)
-  wildcardAccessURL:
+  # (default: <unset>, type: string)
+  wildcardAccessURL: ""
   # Specifies the custom docs URL.
   # (default: <unset>, type: url)
   docsURL: