[MM-36995] Start using db native JSON datatypes (#17930)

* Start using db native JSON datatypes

* Fix syntax to work on MySQL 5.7.12

go.sum

@@ -643,8 +643,8 @@ github.com/markbates/pkger v0.15.1/go.mod h1:0JoVlrol20BSywW79rN3kdFFsE5xYM+rSCQ
 github.com/marstr/guid v0.0.0-20170427235115-8bdf7d1a087c/go.mod h1:74gB1z2wpxxInTG6yaqA7KrtM0NZ+RbrcqDvYHefzho=
 github.com/mattermost/go-i18n v1.11.0 h1:1hLKqn/ZvhZ80OekjVPGYcCrBfMz+YxNNgqS+beL7zE=
 github.com/mattermost/go-i18n v1.11.0/go.mod h1:RyS7FDNQlzF1PsjbJWHRI35exqaKGSO9qD4iv8QjE34=
-github.com/mattermost/gorp v1.6.2-0.20210419141818-0904a6a388d3 h1:VW5cRIZheMbcC8w7RtJyt0hFckdcJ1cNpSUOELsQGE8=
-github.com/mattermost/gorp v1.6.2-0.20210419141818-0904a6a388d3/go.mod h1:QCQ3U0M9T/BlAdjKFJo0I1oe/YAgbyjNdhU8bpOLafk=
+github.com/mattermost/gorp v1.6.2-0.20210714143452-8b50f5209a7f h1:J47te5ubXIEbEaXi/nwStKQ/sLniXACgZ7LhK365YIY=
+github.com/mattermost/gorp v1.6.2-0.20210714143452-8b50f5209a7f/go.mod h1:QCQ3U0M9T/BlAdjKFJo0I1oe/YAgbyjNdhU8bpOLafk=
 github.com/mattermost/gosaml2 v0.3.3 h1:ysWrjp08tpWmo6rV2MQ88Eag/Ttjuj91fZsvibF4/Tg=
 github.com/mattermost/gosaml2 v0.3.3/go.mod h1:Z429EIOiEi9kbq6yHoApfzlcXpa6dzRDc6pO+Vy2Ksk=
 github.com/mattermost/gziphandler v0.0.1 h1:uXHcXF5agnQ6bXabvpiwwwZOlCYoa7mKHH0lxns/o8w=