offer mailto link parsing api

[adbenitez]

mailto link parsing is implemented repeatedly in each UI client, in android mailto link parsing is far from perfect and it is known to be source of issues in the past and not parsing properly all mailto links etc.

it would be nice if core provided an API to simplify this, and avoid repeated implementation accross UIs

[link2xt]

How the API should look like? What function should be provided, which arguments it takes and what it returns?

I remove "good first issue" for now, I think it is more suitable for issues that only require an implementation without any discussion.

[adbenitez]

something like:

parseMailto(mailto: string) : Mailto

type Mailto {
    To []string
    Subject Option(string)
    Body Option(string)
}

an error is thrown if the mailto uri failed to be parsed, empty To is valid, the chatlist is offered for choosing in that case

[adbenitez]

this has low priority tho, all the UIs have some custom mailto parsing currently, just nice to unify and to avoid problems, ex. the parser on android is too strict IIRC causing invalid parsing for some mailto urls that work in apps like k9mail

[link2xt]

So it is going to replace this Android file?
https://github.com/deltachat/deltachat-android/blob/3f581caa8c1fc52128030d65734850438bafb51f/src/org/thoughtcrime/securesms/util/MailtoUtil.java