The PayUmoney payment integration has been moved from Odoo Enterprise into the Community edition. This makes PayUmoney support available to more users without requiring the enterprise-only module, improving payment options for businesses using Odoo Community.

Description of the issue/feature this PR addresses:

Current behavior before PR:

Desired behavior after PR is merged:
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A new activity count button has been added to customer records in CRM, giving users a quick way to view the full history of logged activities for that customer. This helps sales teams understand past interactions faster without navigating through separate reports or grouped views.

Task: https://www.odoo.com/web?#id=21553&view_type=form&model=project.task&action=333&active_id=131&menu_id=4720
Pad: https://pad.odoo.com/p/r.8EHswIXnNc2xRlUe

[ADD]: Add a stat button with history of activities (count of activities) on the Customer form view.
 After Clicking on Activities Count Stat Button, the list view of the activities should be visible.

Kanban cards can no longer be dragged between groups when the grouped field is read-only or date-based. This prevents users from accidentally changing important business records, such as sales orders or invoices, without the required business checks.

Prevent drag'n'drop in the following cases:
- Group by field is read-only
- Group by field is a date or datetime

This is necessary to avoid, for example, changing the state of a sales
order or an invoice without going through all the business logic.

Related to #7047
opw-671697

The badge and challenge screens were cleaned up so employee avatars, form fields, and badge details display correctly. Badge pages now also show a clear counter for employees who have received each badge, making the information easier to find and use.

TASK: https://www.odoo.com/web#id=21433&view_type=form&model=project.task&action=327&menu_id=4720
PAD: https://pad.odoo.com/p/r.PynAYvEXp6qz7G9s

Commit Summery:

<b>First Commit:</b>
Converted styles from sass to less so that avatars, goals render properly in kanban views.

<b>Second Commit:</b>
Fixed the layout issues with badges, challenges form view as well as grant badge wizard form view.

<b>Third Commit:</b>
Created Granted Employees stat-button in badges form view that shows the Number of employees to whom the particular badge is granted.

Core background services, attachments, reporting, website editing, and related technical foundations were migrated to Odoo's newer internal API. This should improve maintainability and consistency while preserving existing business behavior, with fixes included to reduce migration-related regressions.

The PayU Money payment integration is being moved from the Enterprise edition to the Community edition. This makes the payment option more broadly available to Odoo users without changing the core business flow.