getHarmonizedPreview getter for Phase 2 Refactor

[jarmoza]

This addresses #272 by implementing the following:

1. The creation of new store getter getHarmonizedPreview which takes a column name and a data table value and produces a transformed version of that value given the transformation heuristic assigned to the given column. Of note, for this new implementation of functionality that was contained in the previous component annot-age-values is that isoyear transformation is currently being left (commented) out so it can be more fully addressed in a more robust way in its own new issue.
2. The introduction of the appSetting store field as mentioned in our Miro board draft of the store refactor. Currently this only contains the missingValueLabel for the 'string' transformation heuristic.
3. Tests for each different transformation heuristic have been added in store-getter-getHarmonizedPreview.cy.js
4. Correlating adjustments have been made to the annot-continuous-values component and its test file annot-continuous-values.cy.js

[jarmoza]

@rmanaem NOTE: Something is currently preventing our e2e tests from running.

[jarmoza]

@rmanaem Just pushed the e2e yaml change in a new commit. Looks like we're in the green now for tests here too.

[rmanaem]

What's the reason for removing getPreviewValues?

[jarmoza]

getPreviewValues was a to-be-implemented getter placed in the initial refactor of this file. At the moment it's necessary because it's called by the validationItems function in annot-continuous-values, but this will be removed in my next PR for #336 as I've decided to just use the mappedColumns getter to retrieve the same information this unimplemented function would have.

[jarmoza]

@rmanaem PR requested changes committed. And tests are good.

[rmanaem]

👨🏼‍🍳 🥯