[Security Solution] Remove `exceptions_list` and `alert_suppression` from Diffable Rule

[jpdjere]

Currently, the fields exceptions_list and alert_suppression are part of the DiffableRule definition. This means that:

• the fields diffs are currently displayed in the current diffs in the Rule Upgrade UI in the flyout
• would be shown in the new Three Way Diff component as fields to update

However, since we decided in https://github.com/elastic/kibana/issues/186544, that these fields would need to be always updated to their CURRENT version, it makes no sense for them to be displayed in the Three Way Diff component during Rule Upgrade.

Therefore, exclude them from the DiffableRule definition.

This will:

• prevent them from appearing in the Three Way Diff component
• prevent them from being able to be passed as fields in the fields object of the /upgrade/_perform endpoint to set a specific pick_version for them (NOTE: the current logic already forces them to upgrade to the CURRENT version, but removing them from DiffableRule, will completely remove the from the payload schema, and the endpoint will then throw a validation error if included, rather than silently ignoring them)

[elasticmachine]

Pinging @elastic/security-solution (Team: SecuritySolution)

[elasticmachine]

Pinging @elastic/security-detection-rule-management (Team:Detection Rule Management)

[elasticmachine]

Pinging @elastic/security-detections-response (Team:Detections and Resp)