feat: enable editing @supports at-rules in the Styles pane

[shangguan2024]

Summary

• Allow double-clicking a rendered @supports condition in the Elements Styles sidebar to edit it, mirroring the existing @media and @container query editing flow.
• Add the CSS.setSupportsText CDP command across the protocol definitions and the checked-in generated files, and wire it through the SDK and the Styles panel.
• Builds on the earlier "display @supports" change (feat: add @supports at-rule support in the Styles pane #131); this is the second step that makes those at-rules editable.

Changes

• Protocol (browser_protocol.pdl / browser_protocol.json): add setSupportsText command returning CSSSupports.
• Generated (protocol.d.ts, protocol-proxy-api.d.ts, protocol-mapping.d.ts, InspectorBackendCommands.js): add the request/response types, invoke_setSupportsText, the command mapping, and — importantly — the runtime command registration so invoke_setSupportsText exists at runtime.
• SDK (CSSModel.ts): add setSupportsText() following setContainerQueryText().
• Panel (StylesSidebarPane.ts): make _editingMediaCommitted async and dispatch edits by CSSQuery type (CSSContainerQuery / CSSSupports / CSSMedia).

Ported from ChromeDevTools/devtools-frontend@bec8c59.

Test plan

• Balance check: per file, setContainerQueryText and setSupportsText occurrence counts match.
• browser_protocol.json parses as valid JSON.
• tsc type-check passes (exit 0) for both the sdk and elements modules via their generated tsconfigs.
• Runtime smoke: double-click a @supports condition in the Styles sidebar and confirm the edit is applied (requires a backend engine that supports CSS.setSupportsText).