Rollup merge of #106608 - compiler-errors:missing-generics-verbose, r=estebank

Rollup merge of #106608 - compiler-errors:missing-generics-verbose, r=estebank

Render missing generics suggestion verbosely

It's a bit easier to read like this, especially ones that are appending new generics onto an existing list, like ": `, T`" which render somewhat poorly inline.

Also don't suggest `dyn` as a type parameter to add, even if technically that's valid in edition 2015.