[feature + performance] add JSON logging format (#4355)

# Description

Adds JSON logging as an optional alternative log output format. In the process this moves our log formatting itself into a separate subpkg to make it more easily modular, and improves caller name getting with some calling function name caching.

## Checklist

- [x] I/we have read the [GoToSocial contribution guidelines](https://codeberg.org/superseriousbusiness/gotosocial/src/branch/main/CONTRIBUTING.md).
- [x] I/we have discussed the proposed changes already, either in an issue on the repository, or in the Matrix chat.
- [x] I/we have not leveraged AI to create the proposed changes.
- [x] I/we have performed a self-review of added code.
- [x] I/we have written code that is legible and maintainable by others.
- [x] I/we have commented the added code, particularly in hard-to-understand areas.
- [x] I/we have made any necessary changes to documentation.
- [ ] I/we have added tests that cover new code.
- [x] I/we have run tests and they pass locally with the changes.
- [x] I/we have run `go fmt ./...` and `golangci-lint run`.

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4355
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/vendor/codeberg.org/gruf/go-kv/v2/field_format.go b/vendor/codeberg.org/gruf/go-kv/v2/field_format.go
index 8085d4d01..f5db0f123 100644
--- a/vendor/codeberg.org/gruf/go-kv/v2/field_format.go
+++ b/vendor/codeberg.org/gruf/go-kv/v2/field_format.go
@@ -8,8 +8,6 @@ import (
 	"codeberg.org/gruf/go-kv/v2/format"
 )
 
-var formatter format.Formatter
-
 var argsDefault = format.DefaultArgs()
 
 var argsVerbose = func() format.Args {
@@ -29,7 +27,7 @@ func (f Field) AppendFormat(buf *byteutil.Buffer, vbose bool) {
 	}
 	AppendQuoteString(buf, f.K)
 	buf.WriteByte('=')
-	buf.B = formatter.Append(buf.B, f.V, args)
+	buf.B = format.Global.Append(buf.B, f.V, args)
 }
 
 // Value returns the formatted value string of this Field.
@@ -41,6 +39,6 @@ func (f Field) Value(vbose bool) string {
 		args = argsDefault
 	}
 	buf := make([]byte, 0, bufsize/2)
-	buf = formatter.Append(buf, f.V, args)
+	buf = format.Global.Append(buf, f.V, args)
 	return byteutil.B2S(buf)
 }