AI Assistant: add filter value to command default message

[anna-shakhova]

No description provided.

[Copilot]

Pull request overview

This PR improves AI Assistant command feedback for filtering actions in DevExtreme grids by generating a human-readable filter description (based on the grid’s filter panel formatting) and ensuring long command messages remain discoverable in the UI.

Changes:

• Generate a richer default success/failure message for the filterValue AI command by appending formatted filter text (e.g., Apply a filter: [Name] Equals 'Alpha'.).
• Improve command list UX in the AI chat UI by clamping long command text to two lines and exposing the full text via the title attribute on hover.
• Add/adjust unit tests to verify the new message formatting and the title attribute behavior.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
packages/devextreme/js/__internal/grids/grid_core/filter/m_filter_panel.ts	Exposes getFilterText publicly (typed) so AI commands can reuse the filter panel’s human-readable formatting.
packages/devextreme/js/__internal/grids/grid_core/ai_chat/ai_chat.ts	Adds title attribute to command message text elements for full-message hover visibility.
packages/devextreme/js/__internal/grids/grid_core/ai_chat/ai_chat.test.ts	Adds coverage for the new title attribute behavior in command rendering.
packages/devextreme/js/__internal/grids/grid_core/ai_assistant/commands/filtering.ts	Enhances filterValue command messaging by appending formatted filter text via filterPanelView.getFilterText.
packages/devextreme/js/__internal/grids/grid_core/ai_assistant/commands/tests/filtering.test.ts	Updates tests to expect the richer filter message and refines failure mocking to target only filter application.
packages/devextreme-scss/scss/widgets/base/gridBase/layout/aiChat/_variables.scss	Introduces a variable controlling maximum visible lines for command text items.
packages/devextreme-scss/scss/widgets/base/gridBase/layout/aiChat/_index.scss	Applies multi-line clamping styles to AI chat command message text.