fix: cast from db connections with non decoded output

[ivanbelenky]

Describe your changes

As stated on this issue, the connections objects may be set without decoding. Therefore, the stored hash can be a bytes object. This is an issue that clashes with

• schema_out_of_date false positive: different type will force inequality checks to always be True
• IndexMigration expects previous_hash to be of str type

This small check and reassignment for stored_hash, fixes the issue and enables correct detection.

[ivanbelenky]

@sav-norem @bsbodden (saw slorello in PR #663 tagging you, so Ill repeat the pattern)

I am all ears for suggestions &| clarifications on this one

[XChikuX]

Faced this issue myself for bytes storage.

I used the same fix in my production code, so Looks Good to Me

[abrookins]

Let's try it. 👍

[abrookins]

LGTM