Move SchemaMigration from ManageIQ to ManageIQ::Schema plugin
Move SchemaMigration from ManageIQ to ManageIQ::Schema plugin

Fixes https://github.com/ManageIQ/manageiq/issues/16670

chessbyte/manageiq,NickLaMuro/manageiq,chessbyte/manageiq,hstastna/manageiq,andyvesel/manageiq,billfitzgerald0120/manageiq,jameswnl/manageiq,kbrock/manageiq,jrafanie/manageiq,mzazrivec/manageiq,aufi/manageiq,romanblanco/manageiq,mzazrivec/manageiq,andyvesel/manageiq,tinaafitz/manageiq,kbrock/manageiq,yaacov/manageiq,agrare/manageiq,ManageIQ/manageiq,branic/manageiq,billfitzgerald0120/manageiq,ManageIQ/manageiq,jrafanie/manageiq,kbrock/manageiq,jvlcek/manageiq,gmcculloug/manageiq,jvlcek/manageiq,borod108/manageiq,billfitzgerald0120/manageiq,tinaafitz/manageiq,syncrou/manageiq,romanblanco/manageiq,aufi/manageiq,lpichler/manageiq,yaacov/manageiq,andyvesel/manageiq,skateman/manageiq,branic/manageiq,pkomanek/manageiq,tinaafitz/manageiq,d-m-u/manageiq,jvlcek/manageiq,romanblanco/manageiq,NickLaMuro/manageiq,lpichler/manageiq,jameswnl/manageiq,branic/manageiq,d-m-u/manageiq,gmcculloug/manageiq,agrare/manageiq,syncrou/manageiq,mzazrivec/manageiq,lpichler/manageiq,branic/manageiq,borod108/manageiq,jrafanie/manageiq,andyvesel/manageiq,skateman/manageiq,pkomanek/manageiq,djberg96/manageiq,yaacov/manageiq,aufi/manageiq,pkomanek/manageiq,kbrock/manageiq,gmcculloug/manageiq,d-m-u/manageiq,agrare/manageiq,juliancheal/manageiq,juliancheal/manageiq,skateman/manageiq,agrare/manageiq,tinaafitz/manageiq,d-m-u/manageiq,romanblanco/manageiq,NickLaMuro/manageiq,mkanoor/manageiq,chessbyte/manageiq,djberg96/manageiq,syncrou/manageiq,juliancheal/manageiq,borod108/manageiq,billfitzgerald0120/manageiq,chessbyte/manageiq,juliancheal/manageiq,mkanoor/manageiq,pkomanek/manageiq,mkanoor/manageiq,syncrou/manageiq,djberg96/manageiq,mzazrivec/manageiq,borod108/manageiq,jrafanie/manageiq,gmcculloug/manageiq,skateman/manageiq,jameswnl/manageiq,mkanoor/manageiq,hstastna/manageiq,aufi/manageiq,lpichler/manageiq,NickLaMuro/manageiq,jameswnl/manageiq,hstastna/manageiq,jvlcek/manageiq,hstastna/manageiq,yaacov/manageiq,djberg96/manageiq,ManageIQ/manageiq,ManageIQ/manageiq