win: improve disabling of scheduled tasks

This commit:

- Reduces false-positive error messages when disabling scheduled tasks.
  E.g., `ERROR: The specified task name ... does not exist in the system.`
- Centralizes and unifies the logic for disabling scheduled tasks.
- Adds additional documentation, including the existence status of tasks
  on default installations.
- Updates and improves the scripts that disable scheduled tasks.
- Improves consistency of headers in documentation text by removing the
  top margin introduces by headers.

Introduces `DisableScheduledTask` templating function:

- It provides a unified way of disabling scheduled tasks.
- It displays user-friendly messages if a task cannot be found.
- It can now handle multiple tasks found matching a pattern.
- The script now exits with the correct error code.
- It skips enable/disable actions if it's not necessary.

Improve existing scripts:

- 'Disable Google update services':
  - Rename to 'Disable Google background automatic updates'.
  - Add missing scheduled tasks observed in newer versions of Chrome.
  - Change the recommendation for disabling certain tasks to `Strict`,
    as they may interfere with Google Credential Provider as
    side-effect.
  - Separate into more categories/scripts for better granularity and
    documentation.
- 'Disable Adobe Acrobat update services':
  - Rename to 'Disable Adobe background automatic updates'.
  - Separate into more categories/scripts for enhanced granularity and
    documentation.
  - Remove end-of-life `Adobe Flash Player Updater` scheduled task and
    `adobeflashplayerupdatesvc`.
- 'Disable Dropbox automatic update services':
  - Rename to 'Disable Dropbox background automatic updates'.
  - Seperate into more categories/scripts.
- 'Disable Webcam Telemetry (`devicecensus.exe`)':
  - Rename to 'Disable census data collection'.
  - Add the disabling of the "Device User" task under it.
- 'Disable `devicecensus.exe` (telemetry) process':
  - Rename to 'Disable device and configuration data collection tool'.
- 'Disable Nvidia telemetry services':
  - Rename to 'Disable Nvidia telemetry scheduled tasks'.
  - Converted into a category for better granularity.
  - Improve documentation.
- 'Disable Defender tasks':
  - Rename to 'Disable Defender scheduled tasks'.
- 'Disable "Windows Defender ExploitGuard" task':
  - Rename to 'Disable "ExploitGuard MDM policy Refresh" task'.
- 'Remove Nvidia telemetry tasks':
  - Rename to 'Remove Nvidia telemetry packages', as "tasks" often
    refers to scheduled tasks.
- 'Disable Microsoft Office Subscription Heartbeat'
  - Rename to 'Disable "Microsoft Office Subscription Heartbeat" task'.
  - Remove disabling of the undocumented `Office 16 Subscription
    Heartbeat` task.
- 'Disable OneDrive scheduled tasks':
  - Improve documentation.
  - Add disabling of 'OneDrive Per-Machine Standalone Update' task.
- 'Disable Customer Experience Improvement Program'
  - Rename to 'Disable "Customer Experience Improvement Program"
    scheduled tasks' for clarity.