fix: improvement for body tab and RawBody empty string bug (#4273)

* feat(body-label): added label that showing tab is not empty

* fix(body-raw): value is not updated when was empty

---------

Co-authored-by: Dmitry Mukovkin <d.mukovkin@cft.ru>

packages/hoppscotch-common/src/components/http/RawBody.vue

@@ -143,7 +143,7 @@ watch(rawParamsBody, (newVal) => {
 
 // propagate the edits from codemirror back to the body
 watch(codemirrorValue, (updatedValue) => {
-  if (updatedValue && updatedValue !== rawParamsBody.value) {
+  if (updatedValue !== undefined && updatedValue !== rawParamsBody.value) {
     rawParamsBody.value = updatedValue
   }
 })