Convert to ISO8601 fix

[bittib010]

Make it available from main converter script and replace with this as it also checks for current valid ISO format:

function Convert-ToISO8601Duration {
    param (
        [string]$timeValue
    )

    # Check if the input is already in a valid ISO 8601
    if ($timeValue -match '^P(\d+D)?(T(\d+H)?(\d+M)?)?$') {
        return $timeValue  # Return it as-is if it's already in ISO 8601 format
    }

    if ($timeValue -match '(\d+)([HMDhmd])') {
        $value = $matches[1]
        $unit = $matches[2].ToUpper()

        switch ($unit) {
            'H' { return "PT${value}H" }
            'M' { return "PT${value}M" } 
            'D' { return "P${value}D" } 
            default { return $timeValue } # In case of unrecognized format, return input as-is
        }
    }
    else {
        return $timeValue # return it unchanged if not meeting criterias
    }
}