don't rely on star imports from synthDriverHandler

[lukaszgo1]

Link to issue number:

None

Summary of the issue:

Currently a few modules relies on star imports from synthDriverHandler making it unnecessarily difficult to perform refactoring (I've stumbled on this when writing code for #12168)

Description of how this pull request fixes the issue:

Now both settingsDialogs and globalCommands are importing what they need explicitly.

Testing strategy:

• With git grep checked what modules imports synthDriverHander
• For those which imported everything i.e from synthDriver import * I've executed flake8 for the entire file and imported explicitly only whatever they were using.

Known issues with pull request:

None known

Change log entry:

- the `synthDriverHandler` module is no longer star imported into `globalCommands` and `gui.settingsDialogs`  - use `from synthDriverHandler import synthFunctionExample` instead. (#12172)

Code Review Checklist:

• Pull Request description is up to date.
• Unit tests.
• System (end to end) tests.
• Manual tests.
• User Documentation.
• Change log entry.
• Context sensitive help for GUI changes.

[AppVeyorBot]

• System test failure
• Build (for testing PR)

See test results for failed build of commit efca50c7f4

[seanbudd]

I've added a changelog entry and tested this using a method similar to #12126, by checking if the functions that are exported from synthDriverHandler are imported via globalCommands and gui.settingsDialogs