net.http: make parse_form return POST requests with json data as a map with a `json` key, containing the json payload (#14289)

vlib/net/http/request.v

@@ -244,16 +244,22 @@ fn parse_request_line(s string) ?(Method, urllib.URL, Version) {
 //
 // a possible solution is to use the a list of QueryValue
 pub fn parse_form(body string) map[string]string {
-	words := body.split('&')
 	mut form := map[string]string{}
-	for word in words {
-		kv := word.split_nth('=', 2)
-		if kv.len != 2 {
-			continue
+
+	if body.match_glob('{*}') {
+		form['json'] = body
+	} else {
+		words := body.split('&')
+
+		for word in words {
+			kv := word.split_nth('=', 2)
+			if kv.len != 2 {
+				continue
+			}
+			key := urllib.query_unescape(kv[0]) or { continue }
+			val := urllib.query_unescape(kv[1]) or { continue }
+			form[key] = val
 		}
-		key := urllib.query_unescape(kv[0]) or { continue }
-		val := urllib.query_unescape(kv[1]) or { continue }
-		form[key] = val
 	}
 	return form
 	// }

vlib/net/http/request_test.v

@@ -95,6 +95,30 @@ fn test_parse_form() {
 		'a': 'b'
 		'c': ' d '
 	}
+	assert parse_form('{json}') == {
+		'json': '{json}'
+	}
+	assert parse_form('{
+    "_id": "76c",
+    "friends": [
+      {
+        "id": 0,
+        "name": "Mason Luna"
+      }
+    ],
+    "greeting": "Hello."
+  }') == {
+		'json': '{
+    "_id": "76c",
+    "friends": [
+      {
+        "id": 0,
+        "name": "Mason Luna"
+      }
+    ],
+    "greeting": "Hello."
+  }'
+	}
 }
 
 fn test_parse_multipart_form() {