Allow deletion of traces for better workspace organisation

[NasonZ]

Problem

Currently, traces in Laminar are immutable and cannot be deleted. This makes it difficult to maintain an organised workspace as traces accumulate over time.

Use Case

• Workspace becomes cluttered with outdated traces
• No way to remove unnecessary or obsolete traces
• Need to maintain a clean, focused view of relevant traces

Current Workaround

None available - traces cannot be deleted once created

Proposed Solution

Add ability to:

• Delete individual traces
• Bulk delete selected traces
• (Optional) Add confirmation dialog for deletion

Additional Context

While deletion is the primary need, other organisational features like copying or moving traces could be considered for future enhancements to further improve workspace management.

Technical Considerations

• Consider soft deletion vs permanent deletion
• Handling of related spans when deleting traces
• Access controls for deletion permissions

[dinmukhamedm]

sorry we haven't had time to look at this, but I think somebody shall pick this up soon. If not, I will. @NasonZ by the way, would you please submit a PR to add your issue template as something like 'feature-request.yml'? We'd greatly appreciate that