parser: recover from errors in any block

parser: recover from errors in any block

Move error recovery to the common_block definition to handle errors
in any block. Queue those errors and abort parsing once a threshold
is reached.

With this in place, we can continue parsing when errors occur and
show all of them to the user at once.

tests/error.1:3:8-8: Error: syntax error, unexpected '{', expecting string
filter {
       ^
tests/error.1:4:13-13: Error: syntax error, unexpected newline
filter input
            ^
tests/error.1:5:17-17: Error: syntax error, unexpected newline
filter input tcp
                ^
tests/error.1:6:23-23: Error: syntax error, unexpected newline
filter input tcp dport

Signed-off-by: Patrick McHardy <kaber@trash.net>