[tokens] Update build process to account for strings instead of arrays

[matgalla]

Description

Tokens Studio does not currently have support for arrays. All variables that are meant to hold multiple values (i.e. fallback fonts) will need to pull them from a string instead. For example, in src/tokens/semantic/font.json:

Current:

- "value": ["{core.font.family.avenirNext}", "{core.font.family.avenir}", "{core.font.family.helveticaNeue}", "{core.font.family.sansSerif}"],

What Tokens Studio wants:

+ "value": "{core.font.family.avenirNext},{core.font.family.avenir},{core.font.family.helveticaNeue},{core.font.family.sansSerif}",

Proposed Advantages

1. Tokens Studio can properly apply fonts to the typography styles that are exported into Figma
2. Tokens Studio will stop automatically trying to "fix" the syntax when making unrelated updates

Which Component

No final tokens or components are expected to change

Relevant Info

#11902

Calcite package

• @esri/calcite-components
• @esri/calcite-components-react
• @esri/calcite-design-tokens
• @esri/calcite-ui-icons
• @esri/eslint-plugin-calcite-components