Merge the migration guides in the code base

Description

Migration guides are maintained in the wiki and in the source code.

We should have them in only one place (the source code) and link to them from the wiki.

Environment

None

Status

Assignee

Guillaume Smet

Reporter

Guillaume Smet

Fix versions

Labels

None

backPortable

None

Suitable for new contributors

None

Requires Release Note

None

Pull Request

None

backportDecision

None

Components

Priority

Major
Configure