Tries we have

the main inspiration for recent implementations are ART and HAMT

all implementations presently use HAMT-style array maps

all require V: Inline

Trie	key	iteration	subtractive set ops
`Amt`	`impl Inline`	TODO: sorted
`Hamt`	`Hash`	N/A	✓
`Trie`	`impl ReflessObject`	sorted

planned for inclusion