Bug 1831248 - Fix conceal/show button not working properly. r=mtigley

Fixes password input behaviour.
- The password text will be revealed when focused from oustide (i.e not triggered by reveal button )
- The password text will be concealed when blurred.
- The password text will show / hide depending on reveal button state. Edit is possible when password is hidden by reveal button.

**Old behaviour:**
{F4936523}

**Current behaviour:**
{F4936530}

Differential Revision: https://phabricator.services.mozilla.com/D180979

browser/components/aboutlogins/content/components/login-item.mjs

@@ -308,6 +308,13 @@ export default class LoginItem extends HTMLElement {
         break;
       }
       case "blur": {
+        // TODO(Bug 1838494): Remove this if block
+        // This is a temporary fix until Bug 1750072 lands
+        const focusCheckboxNext = event.relatedTarget === this._revealCheckbox;
+        if (focusCheckboxNext) {
+          return;
+        }
+
         if (this.dataset.editing && event.target === this._passwordInput) {
           this._revealCheckbox.checked = false;
           this._updatePasswordRevealState();
@@ -331,9 +338,18 @@ export default class LoginItem extends HTMLElement {
         break;
       }
       case "focus": {
-        const { target } = event;
+        // TODO(Bug 1838494): Remove this if block
+        // This is a temporary fix until Bug 1750072 lands
+        const focusFromCheckbox = event.relatedTarget === this._revealCheckbox;
+        const isEditingMode = this.dataset.editing || this.dataset.isNewLogin;
+        if (focusFromCheckbox && isEditingMode) {
+          this._passwordInput.type = this._revealCheckbox.checked
+            ? "text"
+            : "password";
+          return;
+        }
 
-        if (target === this._passwordDisplayInput) {
+        if (event.target === this._passwordDisplayInput) {
           this._revealCheckbox.checked = !!this.dataset.editing;
           this._updatePasswordRevealState();
         }
@@ -343,6 +359,14 @@ export default class LoginItem extends HTMLElement {
       case "click": {
         let classList = event.currentTarget.classList;
         if (classList.contains("reveal-password-checkbox")) {
+          // TODO(Bug 1838494): Remove this if block
+          // This is a temporary fix until Bug 1750072 lands
+          if (this.dataset.editing || this.dataset.isNewLogin) {
+            this._passwordDisplayInput.replaceWith(this._passwordInput);
+            this._passwordInput.type = "text";
+            this._passwordInput.focus();
+            return;
+          }
           // We prompt for the primary password when entering edit mode already.
           if (this._revealCheckbox.checked && !this.dataset.editing) {
             let primaryPasswordAuth = await promptForPrimaryPassword(