Add MavenPublishModule for maven compatiable repository

[chikei]

more like a POC for #5592, I think there are rooms for sharing code/task between this and SonatypeCentralPublishModule

[lefou]

@chikei Is this code written from scratch? Is it partially copied from other places in the Mill repo? This info would greatly help reviewing it.

[chikei]

It's copied from existing SonatypeCentralPublishModule and replace the publishReleases in publishAll using almost identical from publishSnapshot. Effectively changing the publish flow for release from repo1's staging flow to direct http upload.

Edit: and remove the gpg args from publishAll as well