Add timeout handling for RW-Upgrade scripts

Add timeout handling for RW-Upgrade scripts

Introduced timeout handling for RW-Upgrade scripts execution.

- Added `run-with-timeout.sh` for executing scripts with a specified
  default timeout.
- Modified `update.sh.in` to:
  - Use `run-with-timeout.sh` with the default timeout value.
  - Parse `###Timeout = <value>` in each script for custom timeouts.
  - Default to `INDIVIDUAL_SCRIPT_TIMEOUT` if no custom timeout is set.
  - Reads /etc/upgrade/conf.d/rw-upgrade-scripts.conf and sets the
    timeout value for all scripts based on it, otherwise sets it to
    25 seconds.
  - Ensure backward compatibility for scripts without custom timeouts.
  - Improve error handling for individual and total timeout violations.

This ensures stricter control over script execution timing and
improves the reliability of the RW-Upgrade process.

Change-Id: Id80f8912e7e4a96251e76cd87ea0131ed2700215