LibWeb/CSP: Implement the manifest-src directive

Author: https://github.com/Lubrsi
Commit: 5addbcd61b
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5308
Reviewed-by: https://github.com/shannonbooth

Libraries/LibWeb/CMakeLists.txt

@@ -44,6 +44,7 @@ set(SOURCES
     ContentSecurityPolicy/Directives/FrameSourceDirective.cpp
     ContentSecurityPolicy/Directives/ImageSourceDirective.cpp
     ContentSecurityPolicy/Directives/KeywordSources.cpp
+    ContentSecurityPolicy/Directives/ManifestSourceDirective.cpp
     ContentSecurityPolicy/Directives/Names.cpp
     ContentSecurityPolicy/Directives/SerializedDirective.cpp
     ContentSecurityPolicy/Directives/SourceExpression.cpp