If the boss is unknown, we exclude the log - that is how
BossFilter::filter operates, and it is probably what the user wants if
they specify a -boss filter. However, in filter_early, the default for
unknown bosses was to return Inclusion::Include, which is not consistent
with filter. That lead to some logs being included, parsed and then
thrown away again.

This change makes the behaviour for unknown bosses between filter_early
and filter consistent, and therefore speeds up the search if -boss is
used.

Everybody calls bosses by different names (Soulless Horror vs Desmina,
Super Kodan Brothers, ...), so it might be good to have a list ready in
the help message.

Other names can still be used, but those are the end-user documented
ones now.

With evtclib 0.2, every boss has at least one name without space, so
every boss can be used. Still, for completeness's and consistency's
sake, we want to allow users to also specify boss names with spaces in
them. For example, if we print "Qadim the Peerless" as the name of the
boss, we might expect
    raidgrep -- -boss "Qadim the Peerless"
to work (instead of -boss qadimp). Therefore, we now allow boss names to
be quoted, so that we can properly persist the whitespace.

Having a ::new on each of the filter types was a bit weird, especially
because we returned Box<dyn ...> instead of Self (and clippy rightfully
complained). With this patch, we now have a bunch of normal functions,
and we don't show to the outside how a filter is actually implemented
(or what struct is behind it).

Since our predicates start with -, this sounds like a good heuristic to
prevent something like "raidgrep -- -player" from silently succeeding
but not doing what the user had intended. In this case, we want the
parse error to show and not treat "-player" as a regex.

First, this commit adds a shortcut if only a single argument is given
that can be parsed as a regex. This is to retain the old behaviour of
"raidgrep NAME" just working, without needing to specify -player or
anything.

Secondly, this also re-wraps arguments with spaces (unless there's only
one argument in total). This means that the following should work:
    raidgrep -- -player "Godric Gobbledygook"
instead of either
    raidgrep -- '-player "Godric Gobbledygook"'
    raidgrep -- -player '"Godric Gobbledygook"'
(notice the extra quotes).