Bug 32180: Add required class to labels in ERM

Bug 32180: Add required class to labels in ERM

To test:
1. Apply patch, yarn build
2. Add/edit Agreemnets, make sure all required fields have a red 'required' label
3. Check 'Add new period', 'Add new user', 'Add new license', 'Add new related agreement'.
4. Add/edit Licenses, make sure all required fields have a red 'required' label.

Signed-off-by: Pedro Amorim <pedro.amorim@ptfs-europe.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>