wes4store model.on(datachanged): honor `return false` in event handlers
wes4store model.on(datachanged): honor `return false` in event handlers

* fix `view` check for early stage where grid isn't binded yet

Signed-off-by: Oleg Verych <a5ce24b76737c0ca6b8faa55c4f938064a1695cf@gmail.com>

suprojs/supro,olecom/supro,suprojs/supro,olecom/supro,olecom/supro,suprojs/supro