Add SensitivityAtSpecificity metric

[oguz-hanoglu]

What does this PR do?

Fixes the remaining part of #971
It basically follows the same code structure with this pull request and make the necessary modifications.
Repos like tensorflow include both SensitivityAtSpecificity and SpecificityAtSensitivity, whereas Torchmetrics is missing SensitivityAtSpecificity.

The github discussion at #971 ends with "Feel free to implement the other variant SensitivityAtSpecificity if you guys are interested."

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section? (OH: no such a section, is this a test?)
• Did you make sure to update the docs?
• Did you write any new necessary tests?

PR review

SpecificityAtSensitivity is already included in TorchMetrics. This PR introduces the SensitivityAtSpecificity Metric.

Did you have fun?

[X] Make sure you had fun coding 🙃

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📚 Documentation preview 📚: https://torchmetrics--2217.org.readthedocs.build/en/2217/

[Borda]

@oguz-hanoglu @SkafteNicki seems to be constantly failing on PT 1.10
see: https://dev.azure.com/Lightning-AI/Metrics/_build/results?buildId=189940&view=logs&jobId=95985737-7c02-5ecd-7847-688de4203f7e&j=95985737-7c02-5ecd-7847-688de4203f7e&t=30568a28-ed27-55ff-e099-f25174540c05

[SkafteNicki]

@Borda yes I know. The weird part is that it is assertion errors meaning that the code is running but giving wrong results. So some pytorch operator has changed behaviour since v1.10

[Borda]

we can also allow this method only for newer PT