Added two deprecation decorators

[AntonBallmaier]

Changelog / Overview

Added two function decorators deprecated and deprecated_params as a consistent way of deprecating code.

Motivation

see #1372
Closes #1372

Explanation for Changes

Have a look at the docs...

Testing Status

Further Comments

Checklist

• I have read the Contributing Guidelines
• I have written a descriptive PR title (see top of PR template for examples)
• I have written a changelog entry for the PR or deem it unnecessary
• My new functions/classes either have a docstring or are private
• My new functions/classes have tests added and (optional) examples in the docs
• My new documentation builds, looks correctly formatted, and adds no additional build warnings

Reviewer Checklist

• The PR title is descriptive enough
• The PR is labeled correctly
• The changelog entry is completed if necessary
• Newly added functions/classes either have a docstring or are private
• Newly added functions/classes have tests added and (optional) examples in the docs
• Newly added documentation builds, looks correctly formatted, and adds no additional build warnings

[RickyC0626]

Just some minor documentation and typo changes. I think this is a great feature for internal use, but if we were to release this feature as a separate package, internationalization support for the warning messages would be a big plus.

[naveen521kk]

SGTM

[RickyC0626]

Perhaps we can introduce some decorator utility commands in another PR.