API: libcrmcommon: add pcmk_rule_input_t type

This new type can hold all data needed to evaluate a rule, and is intended to
combine and replace the pe_re_match_data_t, pe_match_data_t,
pe_rsc_eval_data_t, pe_op_eval_data_t, and pe_rule_eval_data_t types. Nothing
uses it as of this commit.