* simplify post_esp32.py
* make sure path has correct "\" or "/" regarding OS
* add os specific path separators
* more path possible issues corrections
* add function to normpath cmd
* set board_build.variants_dir = variants/tasmota correctly for OS
When vscode is ran from the Tasmota folder in Linux, build fails with message :
```Executing task: pio run <
The terminal process failed to launch: Path to shell executable "pio" is not a file of a symlink.```
Renaming pio folder into pio-tools solve the problem.
Note: the problem can still occur if the user have a pio folder in his PATH...