[RFC] Support parsing `Psl\DateTime\Duration` from a string like `P1Y1M1D`

[rauanmayemir]

Is your feature request related to a problem? Please describe.

PHP-native \DateInterval supports instantiating intervals from a duration string which is also perfectly aligned with standard XMLSchema's xs:duration format.

Describe the solution you'd like

/** @throws DateMalformedIntervalStringException */
$duration = Psl\DateTime\Duration::from('P1Y1M1D');

Describe alternatives you've considered

An alternative is either keep using \DateInterval or manually parsing which is error-prone anyway (Psl's highest granularity is 'hour', so it is on the user to convert years, months, days).

[azjezz]

Psl's highest granularity is 'hour'

this was an oversight from me, it should have been years...