[Eva] Removes state_import.ml and options -eva-[save|load]-fun-state.

Makefile

src/plugins/value/engine/compute_functions.ml

src/plugins/value/register.ml

src/plugins/value/utils/state_import.ml

src/plugins/value/utils/state_import.mli

src/plugins/value/value_parameters.ml

src/plugins/value/value_parameters.mli

tests/builtins/Longinit_sequencer.i

tests/builtins/Longinit_sequencer.ml

tests/builtins/oracle/Longinit_sequencer.res.oracle