Refactor account model
- Don't return anymore the account models from the timeline models but instead return the account id and declare the account model in the qml AccountInfo file. This is a more declarative.
- Unify the account id to being the id returned by the API and not the acct field. This now also store the id as a string as it is more compliant with the api doc that explicitely specify that the id might become a string in the future.
- Port m_identity from to a std::shared_ptr so that is can be used in the identityLookup call and fix some weird behavior due to some special cases for the user own identity.
Signed-off-by: Carl Schwan carl@carlschwan.eu