docs: update screenshots and align "shared with" wording in project docs

[prokopetsv]

Problem

Several project documentation pages had stale screenshot URLs pointing to outdated CDN images, and two pages (ownership-and-sharing.md and roles-and-permissions.md) still used the old "available to them" phrasing for Business User access descriptions. This left the docs inconsistent with the "Shared for / Sharing" terminology introduced in the previous rename PR.

Solution

Replaced stale CDN image URLs across three docs pages with updated ones reflecting the current UI. Updated the two remaining "available to them" phrases to "shared with them" to complete the terminology alignment. No logic, UI code, or API contracts were changed.

Changes

• Replaced screenshot URL in contexts.md (Contexts list view)
• Replaced two screenshot URLs in members.md (Created By column and Owners field)
• Replaced screenshot URL in ownership-and-sharing.md (Data Mart ownership settings)
• Updated "available to them" → "shared with them" in ownership-and-sharing.md (Storage access callout)
• Updated "available to them" → "shared with them" in roles-and-permissions.md (Roles Overview table and Business User data access bullet)