Add --log-type option for daserver

[Tristan-Wilson]

This adds the ability to have json logs.

Testing done

$ ./target/bin/daserver --conf.file ../nitro/datestconf/mainnet-ipfs-mirror.conf --log-type json
{"err":"Post \"https://abc.def\": dial tcp: lookup abc.def: no such host","lvl":"eror","msg":"Error running DAServer","t":"2023-10-16T17:39:55.376489742+02:00"}
$ ./target/bin/daserver --conf.file ../nitro/datestconf/mainnet-ipfs-mirror.conf
ERROR[10-16|17:40:01.001] Error running DAServer                   err="Post \"https://abc.def\": dial tcp: lookup abc.def: no such host"

[joshuacolvin0]

LGTM