CfW: Introduce webCommonW3C source set to fix metadata compilation while avoiding code duplication

[eymar]

The goals of this PR:

• Enable back compileJsWasmMainKotlinMetadata tasks
• Fix "common w3c" symbol resolving in IDE

Solution:

• The code with "common w3c" usages is moved to a new folder called "webQuasiCommon"
• jsMain and wasmJsMain source sets include this folder

How to test:

These tasks should be successfull:

./gradlew :mpp:publishComposeJbToMavenLocal -Pcompose.platforms=web,jvm,android // no native to test on linux agents 
./gradlew :compose:mpp:demo:wasmJsBrowserProductionWebpack
./gradlew :compose:mpp:demo:jsBrowserProductionWebpack

Cons:
IDEA treats the new webQuasiCommon as a k/js source set. Meaning we still need to be careful and test the changes (on CI too).

Pros:*
Working with the code in IDE is more convenient now with resolved symbols.
No need for a workaround anymore in user projects.