`Format-Path`: Support expand environment variables

[johlju]

Command proposal

Suggest adding support for expanding environment variables in path with optional parameter, by using:

$Path = [Environment]::ExpandEnvironmentVariables($Path)

Proposed parameters

Parameter	Mandatory	Data type	Description	Default value	Allowed values
ExpandEnvironmentVariable	No	Switch	Replaces the name of each environment variable embedded in the specified string with the string equivalent of the value of the variable. Each environment variable must be quoted with the percent sign character (%).	None	None

Special considerations or limitations

None.