Update @notionhq/client to v2.2.15

[kaspernowak]

Description:

• Bump @notionhq/client from ^1.0.4 to ^2.2.15 in package.json.
• Update corresponding package-lock.json.
• Adjust table and tableRow definitions to match new Notion typings.
• Resolve breaking changes in src/notion/blocks.ts, src/notion/common.ts, and src/parser/internal.ts.

Context:

• Fixes type errors caused by the older Notion client.
• Incorporates new features/fixes from Notion’s v2.x.x releases (table blocks, updated field definitions, etc.).
• Breaking changes were introduced in v2.0.0, see release notes here for additional details.

Testing:

• All tests passing locally.
• Verified table rendering logic against the updated Notion API.
• No regressions identified in existing functionality.

[kaspernowak]

@EndBug Please review this PR, and maybe briefly review the release notes from release v2.0.0 and onwards here to make sure I did not miss anything that requires additional code changes. If you notice anything that requires further changes, I am happy to implement them.