fix: set companyName for credentialApproval

[Phil91]

Description

adjusting the approval mail to include the bpn as company identifier

Why

Since we don't have the company name available in the database of the ssi credential issuer we take the bpn, which is the only available information and set that as a identifier for the company in the approval mailing

Issue

Refs: #215

Checklist

• [x] I have followed the contributing guidelines
• [x] I have performed IP checks for added or updated 3rd party libraries
• [x] I have created and linked IP issues or requested their creation by a committer
• [x] I have performed a self-review of my own code
• [x] I have successfully tested my changes locally
• [x] I have added tests that prove my changes work
• [x] I have checked that new and existing tests pass locally with my changes
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have added copyright and license headers, footers (for .md files) or files (for images)

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud