tests: conditionalize test-treemanifest.t
Parts of the test were assuming the use of revlogs with fnstore
path encoding.
Other parts of the test assumed we could create repos with different
store encodings and that stream clone bundles worked.
Make all of this conditional on running a revlog repo.
Differential Revision: https://phab.mercurial-scm.org/D3112
http://example.com/no/anchor, branches: (None, [])
http://example.com/an/anchor, branches: ('foo', [])
http://example.com/no/anchor/branches, branches: (None, ['foo'])
http://example.com/an/anchor/branches, branches: ('bar', ['foo'])
http://example.com/an/anchor/branches-None, branches: ('foo', [])
http://example.com/, branches: (None, [])
http://example.com/, branches: (None, [])
http://example.com/, branches: ('foo', [])