[enh] Use lombok annotations to all model classes

[fix] Upgrade JavaMail to 1.6.7, to fix startTtl issue (error "No appropriate protocol (protocol is disabled or cipher suites are inappropriate)")

[enh] use a new Converter interface, for compatibility with Spring-data (need by Cesium+ Pod v2)
[enh] Use a new CrudRepository, for compatibility with Spring-data (need by Cesium+ Pod v2)
[enh] Remove DataContext.accountId
[enh] Add DividendService and repository

[fix] Make sure to copy peer.peering, when fill mainPeer on NetworkService.getPeersAsync()
[fix] Add IEnpointApi interface, to be able to extends API (e.g. for gchange)