feat: added retrieval of file type fields

[ChrisAt2at]

• Extracted retrieval of note attachments to separate function
• Introduced isAttachmentPdf member to determine PDF type once per file
• inverted conditional logic on isAttachmentPdf not to use negation
• Added function to retrieve any file type fields. Quickest way to prevent large code refactoring was to convert the file blob to Base64 string
• Bumbed version to .2