[kernel] Uniform naming for loaders/module importers

src/kernel_internals/parsing/logic_lexer.mll

src/kernel_internals/parsing/logic_parser.mly

src/kernel_internals/typing/mergecil.ml

src/kernel_services/ast_data/cil_types.ml

src/kernel_services/ast_printing/cil_printer.ml

src/kernel_services/ast_printing/cil_types_debug.ml

src/kernel_services/ast_printing/logic_print.ml

src/kernel_services/ast_queries/acsl_extension.ml

src/kernel_services/ast_queries/ast_diff.ml

src/kernel_services/ast_queries/cil.ml

src/kernel_services/ast_queries/cil_datatype.ml

src/kernel_services/ast_queries/logic_env.ml

src/kernel_services/ast_queries/logic_env.mli

src/kernel_services/ast_queries/logic_typing.ml

src/kernel_services/ast_queries/logic_typing.mli

src/kernel_services/ast_queries/logic_utils.ml

src/kernel_services/parsetree/logic_ptree.ml

tests/spec/oracle/import.0.res.oracle

tests/spec/oracle/import.1.res.oracle

tests/spec/oracle/import_errors.0.res.oracle