sql/schemachanger: support security invoker views in the declarative schema changer

## Summary

Add support for `CREATE VIEW ... WITH (security_invoker = true)` in the declarative schema changer. Security invoker views check permissions against the invoking user rather than the view owner.

## Describe the solution you'd like

- Handle `n.Options.SecurityInvoker` in the declarative `create_view.go`
- Respect the `AllowViewWithSecurityInvokerClause` session variable gate
- Store the security invoker flag in the view descriptor
- Ensure compatibility with both `CREATE VIEW` and `CREATE OR REPLACE VIEW`
- Add tests

## Code References

- [create_view.go:81](https://github.com/cockroachdb/cockroach/blob/7f85419e8fa/pkg/sql/create_view.go#L81) — legacy security invoker session variable gate
- [create_view.go](https://github.com/cockroachdb/cockroach/blob/7f85419e8fa/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/create_view.go) — declarative schema changer create view implementation

Epic: CRDB-31466

Jira issue: CRDB-60730

Start with pkg/sql/schemachanger/scbuild/internal/scbuildstmt/create_view.go and compare its handling with the legacy gate in pkg/sql/create_view.go around line 81. Trace the view descriptor creation and existing CREATE VIEW and CREATE OR REPLACE VIEW tests, then add coverage for the session-variable gate and security-invoker flag so both statement forms store and honor the option.

Written by the indexing model from the issue text.