Throughput controller percent settings - applying validation check(0-100) and showing % sign to further increase user-friendliness.

**Himanshu** ([Bug 58345](https://bz.apache.org/bugzilla//show_bug.cgi?id=58345&redirect=false)):
Steps -

1. Add a throughput controller.
2. Select percent execution from dropdown.

Present behaviour of jmeter -
1. User can enter any number beyond 100 also.
2. No '%'sign is visible.

Suggested -

1. User should be able to enter a number between 0 and 100 also.
2. % sign should automatically come on the right side of text box.

OS: All

Reproduce the issue by adding a Throughput Controller and selecting percent execution, then inspect the controller's relevant UI and validation behavior. Done means values are restricted to 0–100 and the percent sign is shown beside the input; verify both behaviors in JMeter.

Written by the indexing model from the issue text.