purify exportActions

Purifying exportActions will allow introspecting and modifying it,
which is needed to add progress bar display to it.

Only S3 and WebDAV ran an Annex action while constructing ExportActions.
There was a small performance gain from them doing that, since a
resource was able to be prepared and reused for multiple actions by
Command.Export.

As seen in commit 809cfbbd8a and
5d394023eb S3 and WebDAV actually create a
new handle for each access in normal, non-export use. It doesn't seem
worth making export use of them marginally more efficient than normal
use. It would be better to do that work upfront when constructing the
remote. Or perhaps use a MVar to cache a handle.

This commit was sponsored by Nick Piper on Patreon.

Command/Sync.hs

@@ -691,7 +691,6 @@ seekExportContent rs (currbranch, _) = or <$> forM rs go
   where
 	go r = withExclusiveLock (gitAnnexExportLock (Remote.uuid r)) $ do
 		db <- Export.openDb (Remote.uuid r)
-		ea <- Remote.exportActions r
 		exported <- case remoteAnnexExportTracking (Remote.gitconfig r) of
 			Nothing -> nontracking r
 			Just b -> do
@@ -699,9 +698,9 @@ seekExportContent rs (currbranch, _) = or <$> forM rs go
 				case mcur of
 					Nothing -> nontracking r
 					Just cur -> do
-						Command.Export.changeExport r ea db cur
+						Command.Export.changeExport r db cur
 						return [mkExported cur []]
-		Export.closeDb db `after` fillexport r ea db (exportedTreeishes exported)
+		Export.closeDb db `after` fillexport r db (exportedTreeishes exported)
 		
 	nontracking r = do
 		exported <- getExport (Remote.uuid r)
@@ -720,10 +719,9 @@ seekExportContent rs (currbranch, _) = or <$> forM rs go
 		_ -> noop
 
 
-	fillexport _ _ _ [] = return False
-	fillexport r ea db (t:[]) =
-		Command.Export.fillExport r ea db t
-	fillexport r _ _ _ = do
+	fillexport _ _ [] = return False
+	fillexport r db (t:[]) = Command.Export.fillExport r db t
+	fillexport r _ _ = do
 		warnExportConflict r
 		return False