fix: Block inline images in message signatures (#13772)

# Pull Request Template

## Description

This PR includes, block inline images in message signatures and prevent
auto signature insertion when editor is disabled.

- Strip inline base64 images from signature on save and show warning
message
- Add `INLINE_IMAGE_WARNING` translation key for signature inline image
removal notification
- Add disabled check to `addSignature()` to prevent signature insertion
when editor is disabled
- Add `isEditorDisabled` checks to signature toggle logic in
`toggleSignatureForDraft()`, `replaceText()`, and `clearMessage()`
- Remove unused `replaceText` from the codebase, which belongs to old
`textarea` editor

Fixes
https://linear.app/chatwoot/issue/CW-6588/the-browser-hangs-when-the-message-signature-contains-inline-image

## Type of change

- [x] Bug fix (non-breaking change which fixes an issue)

## How Has This Been Tested?

### Loom video
https://www.loom.com/share/fb556b46a12a4308a737eed732d5ed73


## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [ ] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

---------

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/javascript/dashboard/components/widgets/WootWriter/Editor.vue

@@ -313,7 +313,12 @@ const plugins = computed(() => {
 const sendWithSignature = computed(() => {
   // this is considered the source of truth, we watch this property
   // on change, we toggle the signature in the editor
-  if (props.allowSignature && !props.isPrivate && props.channelType) {
+  if (
+    props.allowSignature &&
+    !props.isPrivate &&
+    props.channelType &&
+    !props.disabled
+  ) {
     return fetchSignatureFlagFromUISettings(props.channelType);
   }
 
@@ -436,6 +441,7 @@ function reloadState(content = props.modelValue) {
 }
 
 function addSignature() {
+  if (props.disabled) return;
   let content = props.modelValue;
   // see if the content is empty, if it is before appending the signature
   // we need to add a paragraph node and move the cursor at the start of the editor
@@ -454,6 +460,7 @@ function addSignature() {
 }
 
 function removeSignature() {
+  if (props.disabled) return;
   if (!props.signature) return;
   let content = props.modelValue;
   content = removeSignatureHelper(
@@ -806,7 +813,7 @@ watch(
 
 watch(sendWithSignature, newValue => {
   // see if the allowSignature flag is true
-  if (props.allowSignature) {
+  if (props.allowSignature && !props.disabled) {
     toggleSignatureInEditor(newValue);
   }
 });

app/javascript/dashboard/components/widgets/WootWriter/ReplyBottomPanel.vue

@@ -128,7 +128,6 @@ export default {
     },
   },
   emits: [
-    'replaceText',
     'toggleInsertArticle',
     'selectWhatsappTemplate',
     'selectContentTemplate',
@@ -277,9 +276,6 @@ export default {
     toggleMessageSignature() {
       this.setSignatureFlagForInbox(this.channelType, !this.sendWithSignature);
     },
-    replaceText(text) {
-      this.$emit('replaceText', text);
-    },
     toggleInsertArticle() {
       this.$emit('toggleInsertArticle');
     },