Use H5Pisa_class to circumvent bug

[mulimoen]

Fixes #218. On the the bug in the issue memory usage decreases from 100MB++ to less than 50kB

@stormmathisen and @smutch Would be great if you tested this

[smutch]

Hi @mulimoen. Thanks for looking in to this.

I can confirm a noticeable improvement for my small test run (3,819 groups with ~11,500 datasets).

Before:

After:

There is a large reduction in persistent 96 byte allocations.

[aldanor]

• Probably makes sense to fix a few clippy complaints as well here?
• Add this to changelog?
• Why do you say it "partially" fixes Memory Leak in Dataset Creation #218? Wasn't this the root of the problem?

[mulimoen]

There are enough breaking clippy complaints that I've opened #220 for those.

Added an entry to the changelog and changed the description of this PR

[aldanor]

Rebase on master?

[aldanor]

👍