vim-patch:9.1.1219: Strange error with wrong type for matchfuzzy() "camelcase"

Problem:  Strange error with type for matchfuzzy() "camelcase".
Solution: Show the error "Invalid value for argument camelcase" instead
          of "Invalid argument: camelcase" (zeertzjq).

Note that using tv_get_string() will lead to confusion, as when the
value cannot be converted to a string tv_get_string() will also give an
error about that, but "camelcase" takes a boolean, not a string.  Also
don't use tv_get_string() for the "limit" argument above.

closes: vim/vim#16926

c4815c157b

runtime/lua/vim/_meta/vimfn.lua

@@ -5817,7 +5817,7 @@ function vim.fn.matchend(expr, pat, start, count) end
 ---     returned.  Zero means no limit.
 ---     camelcase  Use enhanced camel case scoring making results
 ---     better suited for completion related to
----     programming languages. Default is v:true
+---     programming languages.  Defaults to v:true.
 ---
 --- If {list} is a list of dictionaries, then the optional {dict}
 --- argument supports the following additional items: