feat: per-widget hide_comparison toggle for canvas components

[nishantmonu51]

When comparison is enabled on a canvas it applies to every widget. This makes comparison its own per-widget axis so a component can turn it off, or compare against its own range, independently of the canvas toggle and of a local time range.

• New comparison_range renderer property on canvas data components (KPI grid, table/pivot, leaderboard, cartesian charts). Absent inherits the canvas comparison, none turns it off, and a comparison range (rill-PW, a custom start,end pair, ...) overrides it. Comparison intervals are computed against the component's effective time range, local or canvas.
• Inspector: one "Time comparison" selector in the "Time & filters" tab with Inherit from canvas / Off / the comparison presets / Custom. The inherit entry shows what the canvas currently compares against. This replaces the separate toggle and the local comparison pill, so the UI always mirrors the YAML.
• Back-compat: compare_tr inside time_filters is still read (a local time range without it keeps meaning "no comparison", as today) but is no longer written. Enabling a local time range from the UI writes comparison_range: inherit so the widget keeps the comparison the user sees.
• Resolved in one place, BaseCanvasComponent.timeAndFilterStore, since every widget and the open-in-explore link read showTimeComparison from that derived store. updateProperties writes several spec keys in a single YAML update. No backend, proto, or schema change needed.
• The inspector's "Filters" tab is renamed to "Time & filters" since it holds time range, comparison, and dimension filter overrides.
• Docs updated in the canvas data widgets page and the AI canvas instructions; i18n keys added in en.json and es.json.
• E2e coverage in web-local/tests/canvas/filters.spec.ts: a widget can turn comparison off and back to inherit while the canvas comparison stays on; the local time range test now picks its comparison from the new selector.

Checklist:

• Covered by tests
• Ran it and it works as intended
• Reviewed the diff before requesting a review
• Checked for unhandled edge cases
• Linked the issues it closes
• Checked if the docs need to be updated. If so, create a separate Linear DOCS issue
• Intend to cherry-pick into the release branch
• I'm proud of this work!

[AdityaHegde]

Adding a separate toggle makes this confusing. In the example I have toggled the new setting on and have comparison in top level filters, but have toggled off local comparison, leading to a mismatch. But if the new toggle is off comparison selector is not shown at all while the yaml still has it like time_filters: tr=7D+as+of+latest%2FD%2B1D&compare_tr=rill-PP So there is a mismatch in how things are interpreted.

Not a 100% sure what will make this consistent. Perhaps we can add inherit option to time and comparison selectors?