Refactor: Migrate the NCA tab to shiny modules and bslib

[js3110]

Description

Since incorporation of bslib ui layout to data and outputs section, nca section formatting is bad. Needs to be updated so it looks better.

Definition of Done:

• NCA tab refactored to be contained within shiny modules
• NCA tabs reformatted to fit bslib
• All sections correctly formatted in an easy to use and easy to read way.

[m-kolomanski]

In addition, we should finally modularize this tab. #146 adds some changes to nca.R file, so probably this issue should follow. I think part of the issues with code logic in the above PR stems from the fact that this part of the application still lives free instead of being encapsulated.

[js3110]

@m-kolomanski completely agree, and I was already thinking of modularising the tab once #109 and #146 are complete. We can do it as part of this issue, or separately within #63 , what do you think?

[m-kolomanski]

Within this issue, at this point #63 is an "epic" issue, existing to remind of a bigger goal rather than a task on its own right.

I am renaming this issue to reflect the actual wanted changes and we can work within that.