feat(codecs): MessagePack decoder

[keuin]

Summary

This patch adds MessagePack decoder. MessagePack is a JSON-like binary format.

Vector configuration

[sources.in]
type = "stdin"
decoding.codec = "message_pack"

[sinks.out]
type = "console"
inputs = ["in"]
encoding.codec = "json"

How did you test this PR?

I tested it with:

1. Unit test
2. Manual test with above config and MessagePack data:

\x87\xA3\x69\x6E\x74\x01\xA5\x66\x6C\x6F\x61\x74\xCB\x3F\xE0\x00\x00\x00\x00\x00\x00\xA7\x62\x6F\x6F\x6C\x65\x61\x6E\xC3\xA4\x6E\x75\x6C\x6C\xC0\xA6\x73\x74\x72\x69\x6E\x67\xA7\x66\x6F\x6F\x20\x62\x61\x72\xA5\x61\x72\x72\x61\x79\x92\xA3\x66\x6F\x6F\xA3\x62\x61\x72\xA6\x6F\x62\x6A\x65\x63\x74\x82\xA3\x66\x6F\x6F\x01\xA3\x62\x61\x7A\xCB\x3F\xE0\x00\x00\x00\x00\x00\x00

This is:

{
	"int": 1,
	"float": 0.5,
	"boolean": true,
	"null": null,
	"string": "foo bar",
	"array": [
		"foo",
		"bar"
	],
	"object": {
		"foo": 1,
		"baz": 0.5
	}
}

\x92\x81\xA3\x76\x61\x6C\x01\x81\xA3\x76\x61\x6C\x02

This is:

[{"val": 1}, {"val": 2}]

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the no-changelog label to this PR.

References

Notes

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