SINR -> CQI -> MCS conversion in the UL

This code review request is in reference to Bug 1840 (https://www.nsnam.org/bugzilla/show_bug.cgi?id=1840) and to the discussion https://groups.google.com/d/msg/ns-3-users/cRw9Aoxd4mg/2D5GcApEVsgJ .

I changed both lte-amc.cc and lte-amc.h as suggested in the comments on bugzilla, i.e. I duplicated the attribute m_ber to m_berUl and m_berDl, moreover I added GetCqiFromUlSinr and GetMcsFromUlSinr.

Finally, I updated all the scheduler classes with the new code.

Hereafter the results of test.py:

PASS: TestSuite lte-rr-ff-mac-scheduler
PASS: TestSuite lte-pf-ff-mac-scheduler
PASS: TestSuite lte-fdmt-ff-mac-scheduler
PASS: TestSuite lte-tdmt-ff-mac-scheduler
PASS: TestSuite lte-tta-ff-mac-scheduler
PASS: TestSuite lte-fdbet-ff-mac-scheduler
PASS: TestSuite lte-tdbet-ff-mac-scheduler
PASS: TestSuite lte-tdtbfq-ff-mac-scheduler
PASS: TestSuite lte-fdtbfq-ff-mac-scheduler
PASS: TestSuite lte-pss-ff-mac-scheduler
PASS: TestSuite lte-cqa-ff-mac-scheduler