Fix PDF Export

[alexfigtree]

Please describe bug.
PDF save causes crash on both iOS and Android.

Additional context
PDF export needs to work in order to share credentials

[kayaelle]

Added a priority label because issuing of diplomas is imminent and we will want the PDFs to be verifiable.

[alexfigtree]

Team meeting: https://docs.google.com/document/d/1cxKjKE6AfHxvPxYVYkgs6sXrs2Wk5OywWNAGwy1NXls/edit

[alexfigtree]

On hold until team meets again and until we figure out V+ links

[alexfigtree]

Currently blocked by: digitalcredentials/web-verifier-plus#126

[alexfigtree]

Dev team meeting: Have it function in the same way as the Post to LinkedIn option

[alexfigtree]

Implementation details for this ticket: For wallet on share screen:

1. Check if credential is verified, then
2. Check if credential has renderMethod field, then
3. Check if this method has html embedded or a link to an html file
4. If there is custom html provided by the issuer via a template, in the export to PDF code, look through html for a qr code tag provided by the DCC (let's call it qr_code), so that if we search for {qr_code}, we replace what's in the curly braces with an img element of a QR code of the share link.

Goal is to replace any QR codes provided in a custom html template, NOT to add them.

[alexfigtree]

Updated title to reflect work done on PDF fix; QR code implementation now implemented in #650.