[MLGO] Delete InlineSizeEstimatorAnalysis (#167271)
InlineSizeEstimatorAnalysis was used initially to provide rewards for RL
algorithms that preferred more immediate rewards. Now we have moved away
from such training methodologies and this code has been sitting dead in
tree providing a bit of a maintenance burden for a couple of years.
Remove it given it is unused and requires some maintenance. This leaves
around the actual IR2Native model for now as it's used in
`TFUtilsTest.cpp`. Eventually we should probably remove that too.
