feat(client): improve client data types

[Mister-Hope]

Developers should prefer to use useClientData directly if they need multiple composables at one place:

- const frontmatter = usePageFrontmatter()
- const pageData = usePageData()
+ const { fontmatter, pageData } = useClientData()

This PR ensure frontmatter and pageData can be easily typed.

[coveralls]

Pull Request Test Coverage Report for Build 12824782477

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 71.722%

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Totals
Change from base Build 12271244431:	0.0%
Covered Lines:	648
Relevant Lines:	906

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💛 - Coveralls