Add async execution support to the api-ui REST API

[YaroslavLitvinov]

Since we implemented async execution earlier in this PR https://github.com/Embucket/embucket/pull/1637, and closed issue https://github.com/Embucket/embucket/issues/1609 we need to support it in UI as well.

Proposal

• Change createQuery handler POST /ui/queries
  Add payload param: asyncExec to the , reflect changes in openapi spec.
  Keep existing functionality of sync execution when asyncExec=false,
  Run query asynchronously when asyncExec=true
• Add for future use DELETE /ui/queries handler, aborts running query by query_id
  or it can be PATCH /ui/queries, expecting additional payload arg: abort=true/false

[nikitastryuk]

2 proposals:

1. Maybe let's use syncExec (default = false) in POST /ui/queries.
   • syncExec=true → run query synchronously.
   • syncExec=false → run asynchronously (default).

2. POST /ui/queries/{query_id}/abort to explicitly abort a running or queued query.
   A bit clearer than using DELETE or PATCH.

@YaroslavLitvinov WDYT?