tools: bpftool: Complete and synchronise attach or map types

Update bpftool's list of attach type names to tell it about the latest
attach types, or the "ringbuf" map. Also update the documentation, help
messages, and bash completion when relevant.

These missing items were reported by the newly added Python script used
to help maintain consistency in bpftool.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210730215435.7095-4-quentin@isovalent.com