Standardize unmatched wildcard errors

Unmatched wildcard errors during parsing are normally only reported when
run interactively. The switch command was unconditionally reporting them
anyway (and not setting the status to 124). Fix it so switch goes
through the same code path as everything else.
Suppress wildcard errors in functions

Wildcard errors are only supposed to reported when encountered during
interactive use. The old parser also suppressed them if `is_block` was
true. This was lost in the new parser. However, this also suppresses
errors generated from `begin; code_here; end` and other block
constructs.

Instead, check the parser block stack when we hit an error, and suppress
the error if there are any function calls / events / source invocations.
These all indicate that the code being executed came from somewhere
other than the commandline.