Remove unnecessary storage config variables (#344)

* rewire config to not use extraneous serve vars

* rename 'file' to 'local' for consistency

* use Type and Size again

internal/media/util.go

@@ -295,28 +295,28 @@ type imageAndMeta struct {
 
 // ParseMediaType converts s to a recognized MediaType, or returns an error if unrecognized
 func ParseMediaType(s string) (Type, error) {
-	switch Type(s) {
-	case Attachment:
-		return Attachment, nil
-	case Header:
-		return Header, nil
-	case Avatar:
-		return Avatar, nil
-	case Emoji:
-		return Emoji, nil
+	switch s {
+	case string(TypeAttachment):
+		return TypeAttachment, nil
+	case string(TypeHeader):
+		return TypeHeader, nil
+	case string(TypeAvatar):
+		return TypeAvatar, nil
+	case string(TypeEmoji):
+		return TypeEmoji, nil
 	}
 	return "", fmt.Errorf("%s not a recognized MediaType", s)
 }
 
 // ParseMediaSize converts s to a recognized MediaSize, or returns an error if unrecognized
 func ParseMediaSize(s string) (Size, error) {
-	switch Size(s) {
-	case Small:
-		return Small, nil
-	case Original:
-		return Original, nil
-	case Static:
-		return Static, nil
+	switch s {
+	case string(SizeSmall):
+		return SizeSmall, nil
+	case string(SizeOriginal):
+		return SizeOriginal, nil
+	case string(SizeStatic):
+		return SizeStatic, nil
 	}
 	return "", fmt.Errorf("%s not a recognized MediaSize", s)
 }