Support VoiceOver

[scannillo]

DTBTSDK-3248

Reason for changes

• Our buttons did not properly support VoiceOver, a key accessibility feature for users

Summary of changes

• Add accessibilityLabels to each button, so VoiceOver properly reads a full description of the button text

Videos

Button Type	Video Link
PayPal Credit	https://github.com/paypal/paypal-ios/assets/35243507/89b43a90-948f-4411-95c8-246a06d6f389
PayPal Pay Later	https://github.com/paypal/paypal-ios/assets/35243507/85922bb2-deac-476f-9799-3130b77de2ee
PayPal w/ Suffix Text	https://github.com/paypal/paypal-ios/assets/35243507/2c32ea00-aeaa-4cf2-87c7-bfca700463d7
PayPal w/ Prefix Text	https://github.com/paypal/paypal-ios/assets/35243507/e6974bd7-d6bd-4d14-b080-7f17bb895631
Small PayPal Logo	https://github.com/paypal/paypal-ios/assets/35243507/d158e99e-65f1-4325-b149-746ab94efc95

Checklist

• [X] Added a changelog entry
• [ ] On device VoiceOver check

Authors

@scannillo

[scannillo]

couldn't get the demo to run on device

Darn, I made a ticket for us to address this (DTPPCPSDK-1696). I think it might have stemmed from this PR.