[Wasm] Loader improvements

- Output ES modules instead of plain files
- Support -Xwasm-launcher=d8 for d8 shell used in tests and benchmarks.
- Reuse launcher generation logic in CLI and box tests runners.
- Create separate output directory for each box since
  there are multiple output files generated for each test.
- Stop using absolute paths in generate JS files
  to simplify running generated code on different machine
- Remove ">>>" from println output


Merge-request: KT-MR-5729
Merged-by: Svyatoslav Kuzmich <svyatoslav.kuzmich@jetbrains.com>

compiler/testData/cli/js/jsExtraHelp.out

@@ -39,7 +39,7 @@ where advanced options include:
   -Xwasm                     Use experimental WebAssembly compiler backend
   -Xwasm-debug-info          Add debug info to WebAssembly compiled module
   -Xwasm-kclass-fqn          Enable support for FQ names in KClass
-  -Xwasm-launcher=esm|nodejs Picks flavor for the wasm launcher. Default is ESM.
+  -Xwasm-launcher=esm|nodejs|d8 Picks flavor for the wasm launcher. Default is ESM.
   -Xallow-kotlin-package     Allow compiling code in package 'kotlin' and allow not requiring kotlin.stdlib in module-info
   -Xallow-result-return-type Allow compiling code when `kotlin.Result` is used as a return type
   -Xbuiltins-from-sources    Compile builtIns from sources