Update `strHash` with a different implementation

[nexushoratio]

The browser implementation of sha256 is only async. So this cannot be a drop-in replacement.

• Implement
• Migrate
• Retire

[nexushoratio]

Trying to get the async wrapper to work is cumbersome.

Abandoning that approach and updating strHash() instead.

Going with a Jenkins hash instead.

[nexushoratio]

Return in a week or so to retire sha256().