fix(view-engine): rename dx-import to import
fix(view-engine): rename dx-import to import

Renaming the resource import element to “import”. Also, removed the
ability to use template attribute imports.

BREAKING CHANGE

behzad88/templating,jw56578/templating,aurelia/templating,jdanyow/templating,davismj/templating,shanonvl/aurelia-templating,charlespockert/templating,milunka/aurelia-templating,PWKad/templating,michaelgeorgeattard/templating,aurelia/templating,cmichaelgraham/templating,AshleyGrant/templating,tcollard/templating,simudream/templating,JeroenVinke/templating,hitesh97/templating