fix: share the tooltip escape listener

[fredrikblau]

Description

Each tooltip instance currently registers its own document-level Escape key listener. This adds one global listener per mounted tooltip and removes it only with that instance.

This change shares one Escape listener across all mounted tooltips and removes it after the last tooltip is unmounted. Tooltip behavior is unchanged.

Related Issue

• Fixes OcTooltip registers a document keydown listener per element #3171

How Has This Been Tested?

• test environment: Node.js 26.7.0, pnpm 11.22.0
• test case 1: pnpm test:unit --run packages/design-system/src/directives/OcTooltip.spec.ts
• test case 2: pnpm check:types
• test case 3: pnpm lint
• test case 4: pnpm format:check

Types of changes

• Bugfix
• Enhancement (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt (improving code quality without changing functionality)
• Tests (adding or updating tests)
• Documentation (updates to the documentation, readme, or changelog)
• Maintenance (updates to the build process or auxiliary tools and libraries)

[fredrikblau]

Updated as suggested: tooltip elements are tracked only while visible, with the shared Escape listener registered on show and removed after the last visible tooltip is hidden.

Validated with the focused OcTooltip test, formatting check, and ESLint.

[JammingBen]

Thanks!