Convert CellTask test to use bake_compare
convert fixture task to use bake_compare
convert all bake tests to be file comparisons

This makes it much easier to see what is expected, and what is wrong
when the output changes
only used to initialize the bake_compare folder
add some missing comparison files
add more missed templates
More file comparisons
Revert fixture changes

Fixtures are db-sensitive, so it's not pracical to do a full-file
comparison
update trait description
Merge pull request #5249 from AD7six/3.0-bake-tests

Convert bake tests to compare to files