tests : convert test_template_format to test-local templates

test_template_format is different from all other tests, in that
we don't want to use the most minimal template possible, we
actually want to test conversion works with maximal/non-trivial
templates, so copy the two templates used by this test into a
local tests/templates directory, with a README caution that
in general inline-minimal templates are preferred.

Change-Id: Ib5421545103728385992625884f86f2667ee2465