feat: add loki-logger plugin

[bzp2010]

Description

Create the loki-logger plugin.

Add: #9072

Checklist

• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• I have added tests corresponding to this change
• I have updated the documentation to reflect this change
• I have verified that this change is backward compatible (If not, please discuss on the APISIX mailing list first)

[soulbird]

We can write a public function to query the log

[bzp2010]

good idea

[bzp2010]

done

[monkeyDluffy6017]

@soulbird please help to check

[Revolyssup]

@bzp2010 Instead of fetching the loki logs in our function in the tests, what if we use https://vector.dev/docs/reference/configuration/sinks/loki/ ? This is being used in tcp-logger, and there are other pull requests to add the same for other loggers as well. What do you think?

[monkeyDluffy6017]

@Sn0rt please help to review

[monkeyDluffy6017]

LGTM, could you provide the chinese doc?

[bzp2010]

Hi, @monkeyDluffy6017

Since I'm busy with some other things, I can't afford to finish the Chinese document for now. But I think if the code and test of this PR are fine, we can merge it first, and once it is merged, I will create an issue and mark it as the good first issue, expecting some potential contributor to help finish it.

[bzp2010]

Hi, @Revolyssup.

I'd like to understand where this essentially lies in terms of consideration.

I don't know much about vectors, but I think it makes sense to track upstream (i.e. Grafana Loki itself). If we use vector to receive logs, we may have to wait for it once the protocol is upgraded.

[monkeyDluffy6017]

@Revolyssup please help to check

[monkeyDluffy6017]

Since I'm busy with some other things, I can't afford to finish the Chinese document for now. But I think if the code and test of this PR are fine, we can merge it first, and once it is merged, I will create an issue and mark it as the good first issue, expecting some potential contributor to help finish it.

Please remember to create a issue