* changes from Chris's branch and cell model updates
* get base64 value
* handle spaces in image names
* add comments
* add tests for imageCallOut dialog
* format document for hygiene errors
* address comments
* check base64 validity using regex
* replace space with regex
* add parameter and return type
* split into two functions
* move functions to fileUtilities
* correct import
* fix for layering issue
* revert file function changes
* Modified modal styles, limiting height of basic modal to 480px.
* wip - added new attachCalloutDialogStyler. Moved callout-specific styler code out of modal.ts
* Moved attach styler code to workbench/common. Added custom styles to imageCalloutDialog
* Moved styler code into calloutDialog. Added callout-specific theme colors to colorRegistry. Removed color styles from modal and callout stylesheets.
* Added CalloutDialogModal that extends CalloutDialog so that the callout can be instantiated from core. Revised calloutDialog so the position cn be passed in from where it is instantiated.
* Revised refactor of modal and image/link callouts so that callout dialog invoked by core can also use the styler. Removed unused properties from dialog code.
* Added conditional to dialogModal to use correct styler for callouts.
* Cleaned up styles. Modified custom colors.
* Wrapped call to positionCalloutDialog in conditional.
* Style, colors, styler and modal updates to align callout with latest OPAC toolkit styles.
* Moved calloutDialog stylesheet
* Consolidated styler code and added a flexible custom styler to provide values for dialogModal
* Added image callout code.
* Remove image callout dialog until wired fully
* Test fixes
Co-authored-by: chlafreniere <hichise@gmail.com>
