Add document picking support to mobile

[Julesssss]

CC @Jag96

Add ability to add document attachments to chats on mobile. This already exists for web and desktop, but mobile users were only able to upload images.

• Uses DocumentPicker library for native file selection
• Renames our existing ImagePicker class to AttachmentPicker
• Builds custom 'Add document' option into existing lists

Fixed Issues

Fixes https://github.com/Expensify/Expensify/issues/142733

Tests

1) Take Photo

• Press attachment button, then 'Take photo'
• The temporary attachment spinner should display
• Photo should be uploaded as an attachment

2) Upload photo from gallery

• Press attachment button, then 'Choose from gallery'
• The temporary attachment spinner should display
• Photo should be uploaded as an attachment

3)

• Press attachment button, then 'Choose Document'
• Select a file for upload (.pdf, .csv, ect)
• File should be uploaded as an attachment

4)

• Press attachment button, press cancel button
• The temporary attachment spinner should not display

5)

• Press attachment button, press 'Choose Document' button
• Press cancel on the modal that pops up
• The temporary attachment spinner should not display

6)

• Revoke camera permission (or completely reinstall)
• Press attachment button, press 'Take Photo' button
• Deny permission
• The temporary attachment spinner should not display

Screenshots

Android

[Julesssss]

CC @Jag96. My thinking is that the previous ImagePicker should be instead called AttachmentPicker -- as it's responsible for more than just images. After that, it made sense to move both the Image and Document picking logic into the AttachmentPicker. Would be great to get your thoughts at this stage and to confirm the overall structure makes sense.

[Jag96]

I like the idea of moving the Document picker inside the newly renamed AttachmentPicker. Left a couple of comments but looks good so far.

[Julesssss]

Document upload is working, but I'm unsure about a certain behaviour:

When uploading a csv file from web, it is a downloadable file, but when I re attach it from mobile it is parsed and displayed as an image. I imagine this was desired for parsing expense reports, but should chat behave differently?

[shawnborton]

I would think it should upload as a file. It would be awesome if we had file previews at some point, but that's a different feature.

[Jag96]

Looking good, just a couple of questions/recommendations

[stitesExpensify]

LGTM

[Jag96]

LGTM, just a nab

[Jag96]

LGTM, good stuff!