feat(chat): collapse the file panel

[IlyaBondar]

Description:

collapse the file panel

Issues:

• Issue #<TICKET_ID>

UI changes

<Please, provide Screenshots or Figma links>

Checklist:

• the pull request name complies with Conventional Commits
• the pull request name starts with fix(<scope>):, feat(<scope>):, feature(<scope>):, chore(<scope>):, hotfix(<scope>): or e2e(<scope>):. If contains breaking changes then the pull request name must start with fix(<scope>)!:, feat(<scope>)!:, feature(<scope>)!:, chore(<scope>)!:, hotfix(<scope>)!: or e2e(<scope>)!: where <scope> is name of affected project: chat, chat-e2e, overlay, shared, sandbox-overlay, etc.
• the pull request name ends with (Issue #<TICKET_ID>) (comma-separated list of issues)
• I confirm that do not share any confidential information like API keys or any other secrets and private URLs

[IlyaBondar]

/deploy-review

Environment URL: https://chat-ai-dial-chat-pr-2520.nightly-test.deltixhub.io
E2E tests status: success