Everywhere: Convert known short-strings to the infallible String factory

For now, this is limited to strings that are 3 bytes or less. We can use
7 bytes on 64-bit platforms, but we do not yet assume 64-bit for Lagom
hosts (e.g. wasm).

Userland/Libraries/LibGL/Shaders/Shader.cpp

@@ -24,7 +24,7 @@ ErrorOr<void> Shader::add_source(StringView source_code)
 
 ErrorOr<void> Shader::compile()
 {
-    m_info_log = TRY(String::from_utf8(""sv));
+    m_info_log = String {};
 
     GLSL::Compiler compiler;