Support variable replacements for file paths

[rugk]

I tried

Without configuration it runs this:

php --colors=never --teamcity

❌ Error in argument 1, char 1: no argument for option -
Usage: php [options] [-f] <file> [--] [args...]
   php [options] -r <code> [--] [args...]

(So "Automatically finds it in common places:" does not seem to work, too.)

Configuring this VSCode extension like this, so it picks up the locally in the project installed PHPUnit:

{
    "phpunit.phpunit": "${workspaceRoot}/vendor/bin/phpunit"
}

But it then tries to run this:

php ${workspaceRoot}/vendor/bin/phpunit --colors=never --teamcity

❌ Could not open input file: ${workspaceRoot}/vendor/bin/phpunit

Only with the full configuration, it tries to execute the correct binary, at least:

{
    "phpunit.phpunit": "/workspaces/PrivateBin/vendor/bin/phpunit"
}

It still fails with some weird XDebug issue, but that's at least one step further:

php /workspaces/PrivateBin/vendor/bin/phpunit --colors=never --teamcity

❌ Xdebug: [Step Debug] Could not connect to debugging client. Tried: localhost:9000 (through xdebug.client_host/xdebug.client_port).

Proposed suggestion

Support variables like ${workspaceRoot} which seems to be common for VSCode in the extensions.

Reference

I try to setup this for a devcontainer/Codespace on GitHub, see https://github.com/PrivateBin/PrivateBin (just create a new codespace there to reproduce)
extension v3.7.10