Remove new-from-rev from the linter (#1783)

* Fix all revive warnings in the code base

All of these are of the form

```
var Identifier Type = Expr
```

where the `Type` is known from the output of `Expr` and can be omitted
as a result.

* Handle unchecked errors

* Remove new-from-rev

Since the project passes all linter checks now, including older
revisions, we can remove new-from-rev. While here, reorder the linter
config file, and move the enabled linters up and settings down.

* Fix failing test cases

Studio & Performer export tests use local time rather than UTC. This
fixes the test cases so integration test
passes.

pkg/image/thumbnail.go

@@ -46,7 +46,9 @@ func (e *ThumbnailEncoder) GetThumbnail(img *models.Image, maxSize int) ([]byte,
 	}
 
 	buf := new(bytes.Buffer)
-	buf.ReadFrom(reader)
+	if _, err := buf.ReadFrom(reader); err != nil {
+		return nil, err
+	}
 
 	_, format, err := DecodeSourceImage(img)
 	if err != nil {