[Spike] - investigate friendly names for all icon sets

Instead of needing to have prefixed icons e.g. "RhUiArrowDownIcon" and "RhMicronArrowDownIcon" and "ArrowDownIcon", see how feasible it is to create a single "ArrowDownIcon" that has an additional "set" property to control which source path data is rendered.

Should be possible in the writeIcons script before exporting everything, just need to be careful in mapping everything and ensure that icons are named consistently (no arrow-down and down-arrow icons because they would be mapped differently). Need to determine a fallback order for sets (pf/fa > rh-ui > rh-microns > etc?) and default set. Need to figure out documentation because not all icons will have support or data for all sets, and icons may have different default sets.

Jira Issue: PF-3403

issue で指定されている writeIcons スクリプトから始め、エクスポート前にアイコン名とソースパスがどのようにマッピングされているかを追跡します。一貫した名前のマッピング、セットの選択、フォールバックの順序、デフォルトの動作を評価し、そのうえで実現可能性、サポートされていないセットの組み合わせ、およびそこから導かれる API の判断を文書化します。