[Blazor] Investigate pooling strategy around TextChunkPage.

We have a comment on code that explains that we don't benefit from pooling with an ArrayPool (hence why TextChunkPage allocates) but we might consider pooling collections of TextChunkPages that can be reused across requests.

The philosophy is similar, instead of renting/returning individually, we rent in bulk. We can then decide what to do when we are done rendering.

We should also consider adjusting the default page allocation size to 64KB, based on data from https://almanac.httparchive.org/en/2025/page-weight#html-bytes the median is 33KB