fix(paginator): coerce string values

[rafaelss95]

Coerces any string values that are passed to pageIndex, length, pageSize to numbers.

Also, I added the coercion to pageSizeOptions to allow people to pass a string array, e.g: ['1', '5', ...].

Fixes #8624.

[andrewseguin]

LGTM

[mhosman]

This fix is available in a new version???

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