Changes applied here introduce backing up keycards data to and fetch them from waku.
Information about received keycards data is sent via `sync.from.waku.keycards` signal.
Changes applied here introduce backing up profile data (display name and identity
images) to waku and fetch them from waku. Information about those data is sent
as a separate signal to a client via `sync.from.waku.profile` signal.
New signal `sync.from.waku.progress` is introduced which will be used to notify a client
about the progress of fetching data from waku.