Use the router method for button links used for route change

[nozomione]

Context

Currently thehref attribute is used for button links. However, for internal routes (non-external urls), we need to trigger the Next.js router event.

Problem or idea

Button links' href attribute should be replaced with the router method for internal routes so that the route change event will be fired on page change.

Solution or next step

Update all the button links for internal routes to use the router method.