Remember last used path for each tool individually

[vkbo]

Summary:

This PR rewrites the last path handler to store the last used user path for each tool that uses path lookups, instead of only storing one last path entry for everything. The Welcome dialog new project form now uses this to remember the path the user used last time for creating a project.

Related Issue(s):

Closes #1930

Reviewer's Checklist:

• The header of all files contain a reference to the repository license
• The overall test coverage is increased or remains the same as before
• All tests are passing
• All flake8 checks are passing and the style guide is followed
• Documentation (as docstrings) is complete and understandable
• Only files that have been actively changed are committed

[paulkater]

Goodness, you're fast...

[vkbo]

It was a feature I already was planning to add, but it will take a few weeks still before the change reaches the users.

[paulkater]

I already pulled the source and I'm running it. 👍
"I've got to have it, Christ, I've got to be the first on our block." 😉