Handle qualifiers with a string value

[steven-esser]

Currently we throw an exception when creating a packageURL with qualifiers that are strings.

The python version currently handles this, so the JS version should as well.

[Omkaragrawal]

Hey,
Does creating Purl with qualifiers that are string means something like:

pkg:maven/org.apache.xmlgraphics/batik-anim@1.9.1?repository_url=repo.spring.io/\"release\"
or something similar?
Sorry to ask if this is a silly question.

[jkowalleck]

Qualifiers are expected to be a dictionary of strings. see https://github.com/package-url/packageurl-js/blob/9998e463ba5e4ad0be96b52e12497d089bdb0b97/src/package-url.d.ts#L68C3-L70

the described feature would bean, that you could set the property to 'foo=1&bar=baz' and it would be internally converted to a dictionary: {foo:1,bar:'baz'}