implement templates for reference file system

[magland]

Implements the use of templates in reference file system as in fsspec, but does not support the full jinja2 templating.

For example,

{
    "templates": {"u1": "https://some/url", "u2": "https://some/other/url"},
    "refs": {
        ... "/some/key/0": [
            "{{u1}}" 0, 100
        ],
        ...
    }
}

In this case, the "{{u1}}" will be replaced with the value of the "u1" template string.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 91.66667% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 82.55%. Comparing base (bc71a9d) to head (d47fd19).

Files	Patch %	Lines
lindi/LindiH5pyFile/LindiH5pyFile.py	0.00%	2 Missing :warning:
...ndi/LindiH5pyFile/LindiReferenceFileSystemStore.py	96.87%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #51 +/- ## ========================================== + Coverage 82.33% 82.55% +0.21% ========================================== Files 25 25 Lines 1715 1748 +33 ========================================== + Hits 1412 1443 +31 - Misses 303 305 +2 ```

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