Pharo 11 Backport of Fix + Tests for issue #16702 : Trait class side…

[bouraqadi]

… methods sometimes not installed on user classes

[MarcusDenker]

Build fails:

MetacelloNotification: Fetched -> BeautifulComments-tonel.1 --- github://pillar-markup/BeautifulComments:v1.0.0/src --- github://pillar-markup/BeautifulComments:v1.0.0/src
MetacelloNotification: Project: NewToolsDocumentBrowser baseline
MetacelloNotification: ...RETRY->BaselineOfMicrodown
MetacelloNotification: ...RETRY->BaselineOfMicrodown
FileDoesNotExistException: '/tmp/github--pillarmarkupMicrodownintegration219820944924360708700770148181567648417.zip'
File>>openForWrite:
File>>openForRead
File>>readStream
FileHandle>>binaryReadStream
FileSystem>>binaryReadStreamOn:
FileReference>>binaryReadStream
ZipArchive>>readFrom:

This could be a general Pharo 11 build problem