Meta+CMake: Extract Wasm spec tests into the binary directory

Clean up the Wasm spec tests CMake rules to extract and compile the wat
files into wasm files in the LibWasm binary directory instead of its
source directory. Also make the rules more robust to missing host tools,
and use more CMake install rules for the test files rather than relying
on build-root-filesystem.sh. Add some FIXMEs for later, we really
shouldn't be doing installation of test files into /home/anon at the
build-root-filesystem stage in $CURRENT_YEAR. Tests go in /usr/Tests

Meta/Lagom/CMakeLists.txt

@@ -65,7 +65,6 @@ if (ENABLE_FUZZERS OR CMAKE_CROSSCOMPILING)
     set(BUILD_LAGOM_TOOLS OFF)
 endif()
 
-include(wasm_spec_tests)
 include(flac_spec_tests)
 include(lagom_compile_options)
 
@@ -665,13 +664,12 @@ if (BUILD_LAGOM)
             ../../Tests/LibWasm/test-wasm.cpp
             ../../Userland/Libraries/LibTest/JavaScriptTestRunnerMain.cpp)
         target_link_libraries(test-wasm LibCore LibTest LibWasm LibJS)
+        # FIXME: Don't require passing test-common.js path if you only want to pass a custom Test root path
         add_test(
             NAME WasmParser
-            COMMAND test-wasm --show-progress=false
+            COMMAND test-wasm --show-progress=false ${CMAKE_CURRENT_BINARY_DIR}/Userland/Libraries/LibWasm/Tests ${SERENITY_PROJECT_ROOT}/Userland/Libraries/LibJS/Tests/test-common.js
         )
-        set_tests_properties(WasmParser PROPERTIES
-            ENVIRONMENT SERENITY_SOURCE_DIR=${SERENITY_PROJECT_ROOT}
-            SKIP_RETURN_CODE 1)
+        set_tests_properties(WasmParser PROPERTIES SKIP_RETURN_CODE 1)
 
         # Tests that are not LibTest based
         # Shell