[translator/azurelogs] Increase unit test coverage (open-telemetry#39176)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

Every test unit that was using a log file, now compares the full log
structure with the expected one instead of just a few fields.

The previous test units all passed. I have removed them as they are now
redundant.

<!-- Issue number (e.g. open-telemetry#1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Fixes
open-telemetry#39136.

---------

Co-authored-by: Antoine Toulme <[email protected]>

Author: 2 people

pkg/translator/azurelogs/go.mod

@@ -4,6 +4,7 @@ go 1.23.0
 
 require (
 	github.com/json-iterator/go v1.1.12
+	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden v0.123.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest v0.123.0
 	github.com/relvacode/iso8601 v1.6.0
 	github.com/stretchr/testify v1.10.0