Feature/project wizard step input validation feedback

[sharon-wang]

Intent

• More UI scaffolding for Epic: New Project Wizards for Beta #2110

Demo

proj_wiz_input_validation.mp4

Themes

proj_wiz_input_validation_themes.mp4

Approach

• support pre-formatted text in substep feedback by making the WizardSubStep feedback property owner-draw (the parent component defines the feedback element instead of just passing a string)
• show an error and prevent navigating to the next step when the project name is empty or only whitespace
• show a warning but allow navigating to the next step if the project name is an existing directory

QA Notes

The project name input validation does not cover checking if the project name only contains valid symbols (i.e. it is possible to enter any symbols such as $, % and \ which can result in an incompatible directory name depending on the operating system). This sort of validation should be added at the component level, since we need to check valid file/directory text input in various places (project wizard, save plot modal, etc.) -- see #2781.

[timtmok]

LGTM