UI: Ability to temporarily disable/pause individual Segment Overrides (like "commenting out")

### Is your feature request related to a problem?

Our developers frequently create complex feature setups and experiments using multiple Segment Overrides with layered conditions (e.g., targeting by Client Type like Android/iOS, Internal Users, or specific Regional Regulations).

Currently, if an experiment needs to be paused, or a specific segment rule needs to be temporarily deactivated, the only option is to completely delete the segment override from the feature. When we need to re-enable it weeks or months later, developers have to rebuild that complex logic from scratch. This is highly tedious, causes unnecessary friction, and drastically increases the risk of human error.

### Describe the solution you'd like.

We would like the ability to toggle the active state of a specific segment override directly within the feature's UI, effectively "commenting it out."

Disable/Pause Toggle: Add a simple "Active / Paused" toggle switch (or a pause icon) next to each Segment Override row inside the feature detail view.

Visual Feedback: When an override is paused, the UI block should be visually greyed out or marked with a "Dormant" badge.

Evaluation Logic: When paused, the Flagsmith evaluation engine should completely ignore this segment override, falling back to the next active segment or the default feature value, exactly as if the override had been deleted.

### Describe alternatives you've considered

* Deleting and Recreating: The current forced workaround. It destroys the historical configuration and relies on developers perfectly remembering complex multi-condition logic to rebuild it later.
* Using Terraform to "comment out" the block: As mentioned in other feedback, we use Terraform, but relying on TF PRs for every small toggle completely defeats the purpose of having an agile Flagsmith Dashboard.
* Creating duplicate "dummy" features: Cloning the feature just to preserve the segment logic clutters the project workspace and creates technical debt.

### Additional context

Giving developers the ability to "comment out" a segment override aligns perfectly with standard engineering workflows. It allows teams to safely pause experiments, handle seasonal feature toggles (e.g., "Black Friday Promos"), or temporarily roll back a specific cohort's access without permanently destroying the configuration they spent time building.