Add tests with preloaded cache to test impact of caching on repeat operations

[oruebel]

The current tests clean up the cache for fsspec and remfile between runs, so we only see the impact of the cache within the context of the specific operation (e.g, opening the file). It would be interesting to also add tests where we can see the impact of the cache when repeating the same operation with a previously initialized cache so that we can compare how much the cache can improve repeat operations.

One approach to implement this would be to:

• Run the test case first in the setup to prime the cache and then
• Repeat the same operation in the actual test function

[oruebel]

@sinha-r we can add these after we have done a baseline run