Audit error logs and create issues

[oalders]

/var/log/starman/metacpan-web/starman_error.log

The logs are full of various template errors etc. We should try to clean some of these up so that the logs become more useful.

[mohawk2]

Of the smaller -web error logs provided earlier (thanks @oalders!), this came up 39 times:

[2020/07/03 11:37:08] [ERROR] [/search?q="><script%20>alert(String.fromCharCode(88,83,83))</script>] Caught exception in MetaCPAN::Web::Controller::Search->index "Timed out at /home/metacpan/metacpan-web/lib/MetaCPAN/Web/Controller/Search.pm line 78."

The search does give results, but it's quite slow. This probably wants investigating.

[mohawk2]

Of the 545 lines of logs, fully 171 are like:

[2020/07/03 11:19:50] [WARN] [/release/ETHER/Moose-2.1800] failed to writev: -1 errno:32 at /home/metacpan/carton/metacpan-web/lib/perl5/x86_64-linux/Plack/Handler/Gazelle.pm line 255.

That is Gazelle getting an EPIPE (32) when trying to write output. These are suppressed in #2344.

[mohawk2]

A further 39 lines were caused by the issue fixed in #2345.

[mohawk2]

Nearly all the remaining messages are Unicode-related warnings.