use getSymbolicLinkStatus not getFileStatus to avoid crash on broken symlink

Fix crash importing from a directory special remote that contains a broken
symlink.

The crash was in listImportableContentsM but some other places in
Remote.Directory also seemed like they could have the same problem.

Also audited for other places that have such a problem. Not all calls
to getFileStatus are bad, in some cases it's better to crash on something
unexpected. For example, `git-annex import path` when the path is a broken
symlink should crash, the same as when it does not exist. Many of the
getFileStatus calls are like that, particularly when they involve
.git/annex/objects which should never have a broken symlink in it.

Fixed a few other possible cases of the problem.

Sponsored-by: Lawrence Brogan on Patreon

CmdLine/Seek.hs

@@ -109,6 +109,10 @@ withPathContents a params = do
 			a f
 		go matcher checktimelimit ps fs		
 	
+	-- Using getFileStatus not getSymbolicLinkStatus because it should
+	-- fail if the path that the user provided is a broken symlink,
+	-- the same as it fails if the path that the user provided does not
+	-- exist.
 	get p = ifM (isDirectory <$> getFileStatus p)
 		( map (\f -> 
 			let f' = toRawFilePath f