Cts enable obstruction aware

[arthurjolo]

This PR removes the CTS option -obstruction_aware and enables it by default, and adds improvements to prevent metrics degradation:

• Remove CTS option -obstruction_aware
• Insert delay to balance clock gater tree
• Improve clock gater handling to correctly inset delay.

[arthurjolo]

Secure-CI is has few metrics failures and a PR has been created to update them, a7/mock_array and ng45/bp_fe have degradation on timing metrics due to a bad placement decision from obstruction aware, I am already working on fixing this issue.