fix(amazonq): Autofocus to prompt field when Q panel is open

### Problem(s)
- When Q panel opens, it doesn't autofocus to prompt input field
- Inside chat body, if there is a code block inside a list item it shows `<br/>` tags
- Prompt input field in Q Chat tabs doesn't stop after it reaches to the given maxLength
- Links are not behaving as expected for middle mouse clicks inside a chat item.

### Solution(s)
- Added autofocus to prompt field when the panel opens or there is a new tab.
- Removed break generation for list items (which is the supposed way from markedjs and github's own markdown styling)
- Prompt input `maxLength` value was used incorrectly, it was using the function declaration instead of the return value of the function. It is corrected.
- As we do for the clicks, we also mapped the middle clicks (`auxclick`) to the same handler functions.

Related `mynah-ui` changes:
[Autofocus](aws/mynah-ui#48)
[Rest of the fixes](aws/mynah-ui#49)

Author: dogusata

.changes/next-release/bugfix-20d3ae15-c11a-4746-bdfc-222e7821db6c.json

@@ -0,0 +1,4 @@
+{
+  "type" : "bugfix",
+  "description" : "Amazon Q Chat: Prompt input field in Q Chat tabs doesn't stop after it reaches to the given maxLength"
+}

.changes/next-release/bugfix-78d6a195-205c-4cc3-b5d9-a97366014aca.json

@@ -0,0 +1,4 @@
+{
+  "type" : "bugfix",
+  "description" : "Amazon Q Chat: When window gets focus, even though the autoFocus property is set to true, input field doesn't get focus"
+}

.changes/next-release/bugfix-cf7feded-bf79-4e3d-aee8-3d09c79181fe.json

@@ -0,0 +1,4 @@
+{
+  "type" : "bugfix",
+  "description" : "Amazon Q Chat: Inside chat body, if there is a code block inside a list item it shows <br/> tags"
+}

plugins/amazonq/mynah-ui/package-lock.json

@@ -12,7 +12,7 @@
         "lintfix": "eslint -c .eslintrc.js --fix --ext .ts ."
     },
     "dependencies": {
-        "@aws/mynah-ui-chat": "npm:@aws/mynah-ui@4.8.0",
+        "@aws/mynah-ui-chat": "npm:@aws/mynah-ui@4.9.0",
         "@types/node": "^14.18.5",
         "fs-extra": "^10.0.1",
         "ts-node": "^10.7.0",