Add GRDB+Swift 5.7

Also, restore #574 which had been reverted for some reason, leaving only support for Swift 4.2 compatibility :-(

Author: groue

projects.json

@@ -878,7 +878,23 @@
       {
         "version": "4.2",
         "commit": "759c1088a1d9ba94f44009295fd17c20b1375524"
-      }
+      },
+      {
+        "version": "5.0",
+        "commit": "759c1088a1d9ba94f44009295fd17c20b1375524"
+      },
+       {
+         "version": "5.1",
+         "commit": "d290102d9cb5c425fee7260034beaa997d581d86"
+       },
+       {
+         "version": "5.3",
+         "commit": "dd7e7f39e8e4d7a22d258d9809a882f914690b01"
+       },
+       {
+         "version": "5.7",
+         "commit": "2d19cab2b525f885ee8d7efec96093431f6b5f20"
+       }
     ],
     "platforms": [
       "Darwin"