ORM: Add from_bytes classmethod to orm.SinglefileData

[GeigerJ2]

As noted together with @elinscott and @mikibonacci: orm.SinglefileData supports getting its content as bytes via get_content, but did not support setting its contents from bytes directly. This is now made possible with the from_bytes classmethod. A few notes on the implementation:

• One could also modify the existing from_string method, and adapt the behavior depending on the type of the content being passed. However, I feel like the name from_string, in that case, is misleading. It would be more suitable if the method were called from_content (or similar, more generic), however, that is not the case, and we cannot modify it due to backwards-compatibility reasons.
• Users could, in principle, just use .decode('utf-8') themselves on the bytes object they want to store before calling .from_string(), but it might be more convenient to allow directly passing the bytes object via from_bytes, as to not have the burden of conversion on the user.
• The functionality tested in the test_get_content function is now already being tested in the (already existing) test_from_string and the (new) test_from_bytes functions, which check the content of the SinglefileData node after storing. However, I still left it for completeness.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.91%. Comparing base (baf8d7c) to head (435e274).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6653      +/-   ##
==========================================
- Coverage   77.92%   77.91%   -0.00%     
==========================================
  Files         563      563              
  Lines       41668    41671       +3     
==========================================
+ Hits        32464    32465       +1     
- Misses       9204     9206       +2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[mikibonacci]

Hi @GeigerJ2 , LGTM! thanks a lot for the PR, it is very useful