Disable load metadata button when fields aren't passing validation

[rmccar]

What is the context of this PR?

This PR refactors the way buttons are enabled and disabled and updates launcher to disable the "load metadata" button when the correct fields aren't selected

How to review

• Test that the "load metadata" button is only enabled when the metadata fields are selected and/or input
• Test that it is then disabled again when local storage is cleared
• Test that it is enabled and disabled when the metadata fields are selected and/or input and then cleared again

[VirajP1002]

Minor - however, when following the steps:

• I loaded metadata by Remote Schemas where I chose the survey type and schema then the button was enabled
• Then I loaded metadata by Schema Name and this disabled the Load Metadata button as expected
• But then I loaded metadata by Remote Schema again, and I only added the survey type and not the schema name and the button was enabled which I'm guessing isn't correct

Happy to jump in a huddle if that doesn't make sense

[rmccar]

Minor - however, when following the steps:

• I loaded metadata by Remote Schemas where I chose the survey type and schema then the button was enabled
• Then I loaded metadata by Schema Name and this disabled the Load Metadata button as expected
• But then I loaded metadata by Remote Schema again, and I only added the survey type and not the schema name and the button was enabled which I'm guessing isn't correct

Happy to jump in a huddle if that doesn't make sense

Should be fixed now if you want to give it another test when you get chance

[liamtoozer]

Works great for me 👍