Add more parameter types to `Parameters`

[Mv77]

I have been playing with the core.Parameters class and really like it. One limitation is that it restricts the class of parameters that can be time-varying. This PR adds support for a few more classes: booleans, distributions, and functions.

You can imagine passing time-varying parameters of this class if, for instance you want:

• To indicate whether an agent is retired = True | False for some meaningful change in its income process.
• To have a time varying distribution for income shocks. Maybe this period they are normal, and the next they are lognormal.
• To have a time varying tax function.

I have used this class in my ongoing work and have been very happy with it.

• [x] Tests for new functionality/models or Tests to reproduce the bug-fix in code.
• [x] Updated documentation of features that add new functionality.
• [x] Update CHANGELOG.md with major/minor changes.

[Mv77]

@alanlujan91 should this change be reflected in other parts of the code like, say, https://github.com/econ-ark/HARK/blob/6a73c4f32a52ff9404f731761c3b754c1f85d650/HARK/core.py#L95 ?

[Mv77]

Not sure this needs a test?

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 71.69%. Comparing base (bbb07a5) to head (7417c54).

:exclamation: Current head 7417c54 differs from pull request most recent head 8fb9040. Consider uploading reports for the commit 8fb9040 to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1387 +/- ## ========================================== + Coverage 71.53% 71.69% +0.15% ========================================== Files 83 84 +1 Lines 13938 13939 +1 ========================================== + Hits 9971 9993 +22 + Misses 3967 3946 -21 ```

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[alanlujan91]

@MridulS is there a way for pre-commit to automatically upload changes?

[MridulS]

There is pre-commit.ci but it makes changes to the PR branch and you need to make sure the contributors are pulling in all changes before making any new changes locally. I would just strongly suggest to new contributors to use pre-commit locally :)

[alanlujan91]

well, somehow my pre-commit is different than the one in github actions?? @MridulS

[Mv77]

MAC hates me. And I hate it too. It's the same tests as in https://github.com/econ-ark/HARK/pull/1415

Will come back to this when that's merged