AMR: do not enforce 2:1 balance in normal direction

[kidder]

Proposed changes

Remove requirement that h-refinement must have 2:1 balance in the direction normal to faces.

Upgrade instructions

In input files that use AMR, you will need to add EnforceTwoToOneBalanceInNormalDirection: true to the list of Policies

Code review checklist

• [ ] The code is documented and the documentation renders correctly. Run make doc to generate the documentation locally into BUILD_DIR/docs/html. Then open index.html.
• [ ] The code follows the stylistic and code quality guidelines listed in the code review guide.
• [ ] The PR lists upgrade instructions and is labeled bugfix or new feature if appropriate.

Further comments

[kidder]

@nilsvu here is the unfinished (and untested) branch for what you asked about

[kidder]

@nilsvu this is now ready for review. It did not cause any problems when I ran the RandomAmr executables.