Pull extra_specs_ops tests from test_host_filters

First in a series of patches to uncruft the 2000+ line
test_host_filters.py unit test file. This patch moves the
extra_specs_ops tests into its own test file.

Change-Id: I200265be6fbc2df1877f01531f443cff8337cebf
Merge "Pull extra_specs_ops tests from test_host_filters"