Remove duplicate multiline strings pattern and update references

Co-authored-by: brunoborges <129743+brunoborges@users.noreply.github.com>

Author: Copilot

content/strings/multiline-json-sql.json

@@ -34,7 +34,7 @@
     "state": "available",
     "description": "Available since JDK 8+ (improved in 9+)"
   },
-  "prev": "strings/multiline-json-sql",
+  "prev": "strings/string-formatted",
   "next": "strings/string-lines",
   "related": [
     "strings/string-repeat",

content/strings/string-chars-stream.json

@@ -35,11 +35,11 @@
     "description": "Widely available since JDK 15 (Sept 2020)"
   },
   "prev": "strings/string-indent-transform",
-  "next": "strings/multiline-json-sql",
+  "next": "strings/string-chars-stream",
   "related": [
-    "strings/multiline-json-sql",
+    "strings/string-lines",
     "strings/string-strip",
-    "strings/multiline-json-sql"
+    "strings/string-indent-transform"
   ],
   "docs": [
     {

content/strings/string-formatted.json

@@ -39,7 +39,7 @@
   "related": [
     "strings/string-isblank",
     "strings/string-strip",
-    "strings/multiline-json-sql"
+    "strings/string-lines"
   ],
   "docs": [
     {