[RTL] Rename internal GMP types for consistency with E-ACSL public API

src/plugins/e-acsl/gmpz.ml

src/plugins/e-acsl/misc.ml

src/plugins/e-acsl/misc.mli

src/plugins/e-acsl/share/e-acsl/e_acsl_gmp.h

src/plugins/e-acsl/share/e-acsl/e_acsl_gmp_types.h

src/plugins/e-acsl/tests/gmp/oracle/at.1.res.oracle

src/plugins/e-acsl/tests/gmp/oracle/gen_arith.c

src/plugins/e-acsl/tests/gmp/oracle/gen_arith2.c

src/plugins/e-acsl/tests/gmp/oracle/gen_at2.c

src/plugins/e-acsl/tests/gmp/oracle/gen_comparison2.c

src/plugins/e-acsl/tests/gmp/oracle/gen_integer_constant.c

src/plugins/e-acsl/tests/gmp/oracle/gen_integer_constant2.c

src/plugins/e-acsl/tests/gmp/oracle/gen_not2.c

src/plugins/e-acsl/tests/gmp/oracle/gen_quantif2.c

src/plugins/e-acsl/tests/gmp/oracle/longlong.0.res.oracle

src/plugins/e-acsl/tests/gmp/oracle/longlong.1.res.oracle

src/plugins/e-acsl/tests/no-main/oracle/empty.res.oracle

src/plugins/e-acsl/tests/reject/oracle/quantif.res.oracle

src/plugins/e-acsl/tests/runtime/oracle/gen_mainargs.c