FRE-600: Fix code review blockers

- Consolidated duplicate UndoManagers to single instance
- Fixed connection promise to only resolve on 'connected' status
- Fixed WebSocketProvider import (WebsocketProvider)
- Added proper doc.destroy() cleanup
- Renamed isPresenceInitialized property to avoid conflict

Co-Authored-By: Paperclip <noreply@paperclip.ing>

node_modules/eslint/lib/shared/severity.js

@@ -0,0 +1,49 @@
+/**
+ * @fileoverview Helpers for severity values (e.g. normalizing different types).
+ * @author Bryan Mishkin
+ */
+
+"use strict";
+
+/**
+ * Convert severity value of different types to a string.
+ * @param {string|number} severity severity value
+ * @throws error if severity is invalid
+ * @returns {string} severity string
+ */
+function normalizeSeverityToString(severity) {
+    if ([2, "2", "error"].includes(severity)) {
+        return "error";
+    }
+    if ([1, "1", "warn"].includes(severity)) {
+        return "warn";
+    }
+    if ([0, "0", "off"].includes(severity)) {
+        return "off";
+    }
+    throw new Error(`Invalid severity value: ${severity}`);
+}
+
+/**
+ * Convert severity value of different types to a number.
+ * @param {string|number} severity severity value
+ * @throws error if severity is invalid
+ * @returns {number} severity number
+ */
+function normalizeSeverityToNumber(severity) {
+    if ([2, "2", "error"].includes(severity)) {
+        return 2;
+    }
+    if ([1, "1", "warn"].includes(severity)) {
+        return 1;
+    }
+    if ([0, "0", "off"].includes(severity)) {
+        return 0;
+    }
+    throw new Error(`Invalid severity value: ${severity}`);
+}
+
+module.exports = {
+    normalizeSeverityToString,
+    normalizeSeverityToNumber
+};