Add conversion from generic floatting point contract to finite one

Makefile

headers/header_spec.txt

...nel_services/ast_transformations/contract_finite_float.ml

...el_services/ast_transformations/contract_finite_float.mli

src/kernel_services/plugin_entry_points/kernel.ml

src/kernel_services/plugin_entry_points/kernel.mli

src/plugins/wp/wpo.mli

tests/float/contract_finite_float.c

tests/float/oracle/contract_finite_float.res.oracle