Deprecate positional arguments in constructors

[itsdawei]

Description

Deprecate positional arguments in constructor of all objects. This PR is inspired by:

• https://scikit-learn-enhancement-proposals.readthedocs.io/en/latest/slep009/proposal.html
• https://github.com/scikit-learn/scikit-learn/issues/15005
• https://scikit-learn.org/stable/whats_new/v0.23.html#enforcing-keyword-only-arguments

Everything in the constructors are now keyword arguments except for archive and emitter parameters.

TODO

Deprecate positional arguments in:

• [x] Emitters
• [x] Archives
• [x] Schedulers

Fix code in:

• [x] tests
• [x] examples
• [x] tutorials

Status

• [x] I have read the guidelines in CONTRIBUTING.md
• [x] I have formatted my code using yapf
• [x] I have tested my code by running pytest
• [x] I have linted my code with pylint
• [x] I have added a one-line description of my change to the changelog in HISTORY.md
• [x] This PR is ready to go