fix(encryptionKey): align credential and wallet config

[Phil91]

Description

Align the credential and wallet configuration to use the same encryption key

Why

The same key is used for encrypting and decryption the wallet data by different processes.

Issue

Refs: #197

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)

[Phil91]

shouldn't it be the other way around as the wallet encryption key must match the credential encryption key: I mean shouldn't the credential encryption key in the issuer service remain as that is the key which does and will continue doing encrypting?

absolutely right. adjusted.