Add a logging schema version attribute

1. Proposed title of this feature request
Add a Logging schema version attribut

2. What is the nature and description of the request?
As a customer I need to be aware of schema evolution. OCP Logging operator upgrade add new attributes or rearrange existing ones.
When Logging stack is used to send message to an external elasticsearch post processing operations are done. If schema is modified that could lead to processing error and lost messages.

• Add a specific notification in release
• Add "version or tag" attribute in the trace messages to control schema version

3. Why does the customer need this? (List the business requirements here)
Due to banking requirements, customer must ensure logging without any lost. This add a additional control/validation to avoid any logging issue.

4. List any affected packages or components.

• Fluentd
• Documentation