Move find_next_pattern_match() in search.c down

After all calls of it.
Rename find_{next_pattern,and_goto}_match()

Because it searches in both directions and navigates to found position.
Less duplication in find_and_goto_match()
Remove useless enumeration in search.c
Forward declare FileView in search.h
Update comments of search module
Fix search of the first file with no parent dir
Extract find_and_goto_pattern() in search.c
Remove useless wrap parameters
Merge branch 'fix-search-of-first-file'

Fix search of the first element in file list when displaying of parent
directory is disabled.

Additionally start using forward declarations and improve code quality
of the search module.