[PLAY-1625] Fix For PhoneNumberInput CSS Conflict (#3922)

**What does this PR do?** A clear and concise description with your
runway ticket url.
https://runway.powerhrg.com/backlog_items/PLAY-1625


**Screenshots:** Screenshots to visualize your addition/change

![click](https://github.com/user-attachments/assets/3d4a8d5b-4f24-4cf4-990a-d33a15a08dc4)

<img width="1201" alt="Screenshot 2024-11-18 at 11 09 17 PM"
src="https://github.com/user-attachments/assets/8893f8fd-4194-4df2-a130-5b660af92990">



**How to test?** 
1. Test the alpha in nitro-web:
**https://pr44183.nitro-web.beta.px.powerapp.cloud/referral_portal/candidates/employee_referral?mt=Refer+a+Friend**
2. Test the codesandbox here:
**https://codesandbox.io/p/sandbox/typeahead-fixes-zgy482**

#### Checklist:
- [X] **LABELS** Add a label: `enhancement`, `bug`, `improvement`, `new
kit`, `deprecated`, or `breaking`. See [Changelog &
Labels](https://github.com/powerhome/playbook/wiki/Changelog-&-Labels)
for details.
- [X] **DEPLOY** I have added the `milano` label to show I'm ready for a
review.
- [ ] **TESTS** I have added test coverage to my code.

playbook/app/pb_kits/playbook/pb_typeahead/_typeahead.scss

@@ -2,6 +2,7 @@
 @import "../tokens/border_radius";
 @import "../tokens/spacing";
 @import "../tokens/shadows";
+@import "../tokens/positioning";
 
 [class^=pb_typeahead_kit] {
   .typeahead-kit-select__option {
@@ -99,6 +100,7 @@
     .typeahead-kit-select__menu {
       background-color: $bg_dark;
       color: $white;
+      z-index: $z_1;
     }
     .typeahead-kit-select__option:hover {
       background-color: $active_dark;
@@ -182,6 +184,7 @@
   }
 
   .typeahead-kit-select__menu {
+    z-index: $z_1;
     .typeahead-kit-select__menu-list {
       padding: 0;
     }