Merge branch 'sg/rebase-progress' into maint

Use "Erase in Line" CSI sequence that is already used in the editor
support to clear cruft in the progress output.

* sg/rebase-progress:
  progress: use term_clear_line()
  rebase: fix garbled progress display with '-x'
  pager: add a helper function to clear the last line in the terminal
  t3404: make the 'rebase.missingCommitsCheck=ignore' test more focused
  t3404: modernize here doc style

cache.h

@@ -1759,6 +1759,7 @@ void setup_pager(void);
 int pager_in_use(void);
 extern int pager_use_color;
 int term_columns(void);
+void term_clear_line(void);
 int decimal_width(uintmax_t);
 int check_pager_config(const char *cmd);
 void prepare_pager_args(struct child_process *, const char *pager);