adapt to changes in gix-actor.

Stop trimming the email at parsing time.
We see poorly formatted emails with a space at the end in real Git repos
and we wish for the gitoxide representation for such commits to
roundtrip.

Propagate the fix from `gix-actor` and add a test to show we now
roundtrip.

Author: pierrechevalier83

gix-object/tests/fixtures/commit/email-with-space.txt

@@ -0,0 +1,5 @@
+tree 1b2dfb4ac5e42080b682fc676e9738c94ce6d54d
+author Sebastian Thiel <sebastian.thiel@icloud.com > 1592437401 +0800
+committer Sebastian Thiel <sebastian.thiel@icloud.com> 1592437401 +0800
+
+In the author line, the email is followed by a space

gix-object/tests/object/encode/mod.rs

@@ -87,6 +87,7 @@ mod commit {
     round_trip!(
         gix_object::Commit,
         gix_object::CommitRef,
+        "commit/email-with-space.txt",
         "commit/signed-whitespace.txt",
         "commit/two-multiline-headers.txt",
         "commit/mergetag.txt",