Adds extension template for cash management POS UI extensions

[Profilist]

https://github.com/shop/issues-retail/issues/16072

Background

As part of Retail Checkout's Extensible Cash Management on POS project, we introduce the following new extension targets:

• pos.cash-tracking-session-details.block.render
• pos.cash-tracking-session-details.action.menu-item.render
• pos.cash-tracking-session-details.action.render
• pos.cash-tracking-session-details.block.render-before
• pos.cash-tracking-session-float.block.render-before
• pos.purchase.post.block.render-before

This PR adds a new POS UI cash management extension template for all the pos.cash-tracking-session-details.x targets to follow conventions of having only 1 .liquid file for each target type.

Solution

Added a new pos-ui-extension-cash-management template that follows the conventions of other POS UI extention templates:

• Support for four flavors: JavaScript, JavaScript React, TypeScript, and TypeScript React
• Implementation of four extension points:
  • Action component for modal presentation
  • Block component for session summary section
  • MenuItem component for displaying the modal
  • Banner component for alerts on top of the session section

The template is registered in templates.json with the identifier pos_ui_cash_management.

Checklist

• I have 🎩'd these changes
• I have squashed my commits into chunks of work with meaningful commit messages

[Profilist]

• Adds extension template for cash management POS UI extensions #297 👈 (View in Graphite)
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.