prep for fixing find --branch --unlocked

Added LinkType to ProvidedInfo, and unified MatchingKey with
ProvidedInfo. They're both used in the same way, so there was no real
reason to keep separate.

Note that addLocked and addUnlocked still set matchNeedsFileName,
because to handle MatchingFile, they do need it. However, they
don't use it when MatchingInfo is provided. This should be ok,
the --branch case will be able skip checking matchNeedsFileName,
since it will provide a filename in any case.

Annex/Import.hs

@@ -454,11 +454,12 @@ importKeys remote importtreeconfig importcontent thirdpartypopulated importablec
 				when (Utility.Matcher.introspect matchNeedsFileContent matcher) $
 					giveup "annex.largefiles configuration examines file contents, so cannot import without content."
  				let mi = MatchingInfo ProvidedInfo
-					{ providedFilePath = f
+					{ providedFilePath = Just f
 					, providedKey = Nothing
-					, providedFileSize = sz
+					, providedFileSize = Just sz
 					, providedMimeType = Nothing
 					, providedMimeEncoding = Nothing
+					, providedLinkType = Nothing
 					}
 				islargefile <- checkMatcher' matcher mi mempty
 				metered Nothing sz $ const $ if islargefile
@@ -703,11 +704,12 @@ matchesImportLocation :: FileMatcher Annex -> ImportLocation -> Integer -> Annex
 matchesImportLocation matcher loc sz = checkMatcher' matcher mi mempty
   where
 	mi = MatchingInfo $ ProvidedInfo
-		{ providedFilePath = fromImportLocation loc
+		{ providedFilePath = Just (fromImportLocation loc)
 		, providedKey = Nothing
-		, providedFileSize = sz
+		, providedFileSize = Just sz
 		, providedMimeType = Nothing
 		, providedMimeEncoding = Nothing
+		, providedLinkType = Nothing
 		}
 
 notIgnoredImportLocation :: ImportTreeConfig -> CheckGitIgnore -> ImportLocation -> Annex Bool