Add document icon to upload file items

Purpose: Add document icon in front of the upload file item name

Notes:

• This scenario was split from UIDATIMP-37

Scenario

• Given the File Upload component
• The file icon should appear in front of the file name (see 1-Uploading a file.png in attachments).
• Note: the icon should be the optional element in the context of the central component

Note: that change requires changes in stripes-components repository, as all icons should be added there. After PR for adding icon is merged, additional PR should be created in ui-data-import repository for adding the icon to the file items.