## Context
We would like to start leveraging more messageFolders during messageSync
which would allow users to select folders they want to sync on their
mailbox. MessageFolder is an abstraction that means folder for
Microsoft, labels for Gmail, not supported for IMAP.
## What
1) We do not aim to build a FE now but we would like to take it into a
consideration if they have been modified through API. So **out of
scope**
2) MessageFolders will be synced regularly from Gmail, Microsoft. This
is currently partially done and improving it is **out of scope**
3) Change: we were having two synchronization mechanism so far:
FULL_SYNC (first time, or when no cursor is present) and PARTIAL_SYNC
(when we have a cursor, we can fetch the diff since the last pull). This
Full vs Partial mode was a high level concept. We now think it's an
driver implementation detail (and can be inferred from the existence of
a cursor). Why making this change now: as we are trying to pull several
folders, a folder could need a full sync if it had no cursor, and
another a partial if it has one. It does not make sense anymore to have
this full vs partial difference at MessageChannel level
4) Once we are sure this work, we can start syncing different folders on
Gmail side (the case for the user it to be able to fetch Promotion
label)
## Implementation strategy
1) Re-use PartialMessageList implementation / API and rename it to
MessageList at it's more complete
2) re-use driver level fullMessageList methods and call them
messageListWithoutCursor
3) make sure that these method are folder specific
## Tests
### Gmail
- Fresh fetch (without cursor): OK
- Message import: OK
- Additional fetch (with messageChannel cursor): OK
### Microsoft
- Fresh fetch (without cursor): OK
- Message import: OK
- Additional fetch (with messageChannel cursor): OK
### Imap
- Fresh fetch (without cursor): OK
- Message import: OK
- Additional fetch (with messageChannel cursor): OK
8b5eb04b07