MBS-10402: Add async report generation

[PM84]

Fixes #168
And does LOTS of coding style fixes to fit the new moodle coding styles

This PR consists of two commits.

1. Fixing coding styles because of new moodle CS.
2. Implementing new functionality manual_async

---

The manual_async runable mode enables administrators to execute resource-intensive SQL queries asynchronously without blocking the web interface, improving user experience for long-running reports.

User workflow:

1. User triggers report execution via "Run in background" action
2. System creates an execution record with pending status
3. Adhoc task is queued for processing
4. User receives immediate confirmation with link to executions overview
5. Background task executes query and stores results as CSV
6. User receives notification upon completion
7. Results are downloaded via file storage API

Technical implementation

Core components:

Adhoc task: \report_customsql\task\execute_query_adhoc handles query execution
Execution manager: \report_customsql\local\execution_manager manages lifecycle and status transitions
Executions table: \report_customsql\table\executions_table provides filterable overview of all executions
File storage: Results stored in Moodle file API using report_customsql component and execution filearea

Key features:

• Streaming CSV output for memory efficiency
• Row-by-row processing to handle large result sets
• Capability-based access control (report/customsql:executebackground)
• Cancellation support with graceful shutdown
• Automated cleanup task for retention management
• Notifications API integration

New Capabilities required

• report/customsql:executebackground - Trigger background execution
• report/customsql:viewallexecutions - View all users' executions (optional)

Configuration

Administrators can configure via plugin settings:

• Maximum execution retention period
• Maximum concurrent executions
• File storage limits

Testing

• Extensive phpunit tests included
• Extensive behat tests included

Comparison: manual vs manual_async

Aspect	manual	manual_async
Execution	Synchronous	Asynchronous
UI blocking	Yes	No
Result delivery	Immediate	Queued notification
Memory usage	Limited by PHP	Streaming (scalable)
Timeout risk	High	None
User experience	Wait on page	Continue working