Tag add/remove/change lines unconditionally with [A], [D], [C].

Tag add/remove/change lines unconditionally with [A], [D], [C].

These tags were previously only emitted by the default reporter if the
there were more than 100 (hard-coded constant) items in a a list. The
leaf reporter emitted them unconditionally. This change simplifies the
code, makes output more consistent and makes it easier to interpret
diffs of diff output.

Additionally, in the reporting of changed unreachable types, the
indentation and quoting for the deleted and added cases was missing.
This patch corrects these issues.

Finally, when doing package differences, there were no tags for
deleted/added binaries. This patch adds them.

	* src/abg-default-reporter.cc (report): In the corpus_diff
	override, remove calculations of number of changes (total) and
	comparisons against arbitrary threshold (large_num); emit [A],
	[D], [C] tags unconditionally.
	* src/abg-reporter-priv.cc
	(maybe_report_unreachable_type_changes): Remove comparisons of
	number of changes against arbitrary threshold (large_num);
	emit [A], [D], [C] tags unconditionally; fix quoting of
        deleted unreachable types; fix indentation of changed
	unreachable types.
	* tools/abipkgdiff.cc (compare_prepared_userspace_packages):
	Emit [D] and [A] tags for removed and added binaries.
	* tests/data/test-*/*report*.txt: In 109 report files, add
        tags [A], [D], [C] tags and correct some indentation and
        quoting.

Signed-off-by: Giuliano Procida <gprocida@google.com>