Rework of Sklearn Metrics (#1327)

* Create utils.py

* Create __init__.py

* redo sklearn metrics

* add some more metrics

* add sklearn metrics

* Create __init__.py

* redo sklearn metrics

* New metric classes (#1326)

* Create metrics package

* Create metric.py

* Create utils.py

* Create __init__.py

* add tests for metric utils

* add docstrings for metrics utils

* add function to recursively apply other function to collection

* add tests for this function

* update test

* Update pytorch_lightning/metrics/metric.py

Co-Authored-By: Jirka Borovec <[email protected]>

* update metric name

* remove example docs

* fix tests

* add metric tests

* fix to tensor conversion

* fix apply to collection

* Update CHANGELOG.md

* Update pytorch_lightning/metrics/metric.py

Co-Authored-By: Jirka Borovec <[email protected]>

* remove tests from init

* add missing type annotations

* rename utils to convertors

* Create metrics.rst

* Update index.rst

* Update index.rst

* Update pytorch_lightning/metrics/convertors.py

Co-Authored-By: Jirka Borovec <[email protected]>

* Update pytorch_lightning/metrics/convertors.py

Co-Authored-By: Jirka Borovec <[email protected]>

* add doctest example

* rename file and fix imports

* added parametrized test

* replace lambda with inlined function

* rename apply_to_collection to apply_func

* Separated class description from init args

* Apply suggestions from code review

Co-Authored-By: Jirka Borovec <[email protected]>

* adjust random values

* suppress output when seeding

* remove gpu from doctest

* Add requested changes and add ellipsis for doctest

* forgot to push these files...

* add explicit check for dtype to convert to

* fix ddp tests

* remove explicit ddp destruction

Co-authored-by: Jirka Borovec <[email protected]>

* add sklearn metrics

* start adding sklearn tests

* fix typo

* return x and y only for curves

* fix typo

* add missing tests for sklearn funcs

* imports

* __all__

* imports

* fix sklearn arguments

* fix imports

* update requirements

* Update CHANGELOG.md

* Update test_sklearn_metrics.py

* formatting

* formatting

* format

* fix all warnings and formatting problems

* Update environment.yml

* Update requirements-extra.txt

* Update environment.yml

* Update requirements-extra.txt

* fix all warnings and formatting problems

* Update CHANGELOG.md

* docs

* inherit

* docs inherit.

* docs

* Apply suggestions from code review

Co-authored-by: Nicki Skafte <[email protected]>

* docs

* req

* min

* Apply suggestions from code review

Co-authored-by: Tullie Murrell <[email protected]>
Co-authored-by: Jirka Borovec <[email protected]>
Co-authored-by: Jirka <[email protected]>
Co-authored-by: Adrian Wälchli <[email protected]>
Co-authored-by: Nicki Skafte <[email protected]>
Co-authored-by: Tullie Murrell <[email protected]>