Update GitHub issue and pull request templates to reflect the current development workflow details

Describe the Task

Some of the details in the GitHub issue and pull request templates are out of sync with the current development workflow. Update the contents of them to make them accurate. Use the MET issue as a guide. Add "Add any new Python packages to the METplus Components Python Requirements table." as a question in the Pull Request Template. Also, update the applicable Issue Templates, adding to the checklist "For any new datasets, an entry to the METplus Verification Datasets Guide". To the Pull Request templates, add to the checklist "Add any new datasets to the METplus Verification Datasets Guide](https://metplus.readthedocs.io/en/latest/Verification_Datasets/index.html)".

Time Estimate

1 hour

Sub-Issues

Consider breaking the task down into sub-issues. None needed

Relevant Deadlines

List relevant project deadlines here or state NONE.

Funding Source

2793521

Define the Metadata

Assignee

[x] Select engineer(s) or no engineer required
[ ] Select scientist(s) or no scientist required

Labels

[x] Select component(s)
[x] Select priority
[x] Select requestor(s)

Projects and Milestone

[x] Select Repository and/or Organization level Project(s) or add alert: NEED CYCLE ASSIGNMENT label
[x] Select Milestone as the next official version or Future Versions

Define Related Issue(s)

Consider the impact to the other METplus components.

[x] METplus, MET, METdataio, METviewer, METexpress, METcalcpy, METplotpy

Task Checklist

See the METplus Workflow for details.

[ ] Complete the issue definition above, including the Time Estimate and Funding Source.
[ ] Fork this repository or create a branch of develop. Branch name: feature_<Issue Number>_<Description>
[ ] Complete the development and test your changes.
[ ] Add/update log messages for easier debugging.
[ ] Add/update unit tests.
[ ] Add/update documentation.
[ ] Add any new Python packages to the METplus Components Python Requirements table.
[ ] Push local changes to GitHub.
[ ] Submit a pull request to merge into develop. Pull request: feature <Issue Number> <Description>
[ ] Define the pull request metadata, as permissions allow. Select: Reviewer(s) and Development issues Select: Repository level development cycle Project for the next official release Select: Milestone as the next official version
[ ] Iterate until the reviewer(s) accept and merge your changes.
[ ] Delete your fork or branch.
[ ] Close this issue.

dtcenter / METplus