rhg: Rename some revlog-related types and methods
Use "data chunck" and "data" for a revlog entry’s data before and after
resolving deltas (if any), repsectively.
The former `FilelogEntry` actually only contains data, rename it to
`FilelogRevisionData` accordingly. This leaves room to later have a
`FilelogEntry` type that wraps `RevlogEntry`.
Differential Revision: https://phab.mercurial-scm.org/D11959
$ hg init
$ echo a > a
$ hg ci -Ama
adding a
$ hg an a
0: a
$ hg --config ui.strict=False an a
0: a
$ echo "[ui]" >> $HGRCPATH
$ echo "strict=True" >> $HGRCPATH
$ hg an a
hg: unknown command 'an'
(use 'hg help' for a list of commands)
[10]
$ hg annotate a
0: a
should succeed - up is an alias, not an abbreviation
$ hg up
0 files updated, 0 files merged, 0 files removed, 0 files unresolved