Create examine method for ordinal CRM models

[Puzzled-Face]

An examine method for ordinal CRM models is required.

Consider modularising using S4 helper methods in preparation for creating a single generic examine method for all model types.

[Puzzled-Face]

This is a larger change than I first imagined. Therefore, break it down into sub-tasks:

• Create RuleDesignOrdinal and DesignOrdinal classes, mimicking RuleDesign and Design classes. [Create RuleDesignOrdinal and DesignOrdinal classes #766]
• Create generic helper functions to
  • h_examine_create_results_table: create an empty results table (columns dose, DLTs, nextDose, stop and increment for Designs and dose, Grade0, Grade1, ..., Grade<n>, nextDose, stop and increment for DesignOrdinals)
  • h_examine_get_toxicity_combos: generate all possible combinations of toxicity counts for a given cohort size
  • h_examine_update_basedata: add a new "no observed toxicity" cohort to baseData
  • h_examine_extract_no_tox_results: extract results for no obserbed toxicities in the current cohort
  • Possibly more
• Create examine-DesignOrdinal method