Const fold splat tensors for TFLite AddOp, SubOp, MulOp

The constant folding rules assumes value attributes of operands are already
verified to be in good standing.

For each op in the above, the constant folding rules support both integer and
floating point cases. Broadcast behavior is also supported as per the semantics
of TFLite ops.

This CL does not handle overflow/underflow cases yet.

PiperOrigin-RevId: 229441221