Improved Excel button

[aclark02-arcus]

Closes #96. This PR is currently an initial placeholder that generates the most basic of excel buttons using the "Buttons" extension for {DT}.

Some possible enhancements include:

• styling and/or repositioning the button
  • Moved button to right-hand side
• making the button disappear or disabled when no data exists in the table
  • Button only shows up on common forms & study forms, plus the queries table
• Add excel button option to golem config
• styling the output in excel to maintain bold (new / updated) records
  • Seems tricky (Stack Overflow) so I'll leave this out for now.
• Improving the the specificity of the filename (Right now, all tables output a generic name).
  • See Improved Excel button #122 (comment)

[LDSamson]

It would be nice if we could reposition it is not the primary visual that people should look at when being presented by the table. Users will look for it if needed. Should we also disable it by default and only enable in the tables in which it is needed? Or add a toggle in the app's settings enable download excel buttons or something similar?

[aclark02-arcus]

View of filename's when downloading listings from different forms is below. Naming convention is as follows:

{"clinsight", [form], [patient], [timestamp]}

Notice that if "show all patients" is selected, the filename will reflect this.

[aclark02-arcus]

Moved button to right-hand side so that it's not the first thing you see, and converted the text to just an icon

[aclark02-arcus]

@jthompson-arcus, got the coveted ✅

[aclark02-arcus]

eh, converting to draft since I lost the ✅ when merging dev -> devex -> ac-96. Will need to re-assess R CMD Check

[aclark02-arcus]

@jthompson-arcus, this is ready for review.

Regarding one of your earlier questions, I chose the path of creating a helper function to configure DT ext / options instead of altering custom_datatable() because this download button only impacts a few tables and I didn't want to add another argument for input$show_all_data etc.

But, it's all up for debate, so I'm all ears if you have comments.

[jthompson-arcus]

Few comments below.