Fix freeing in a few places

[DL6ER]

What does this implement/fix?

For this PR I went through all free invocations I could find and fixed some. Mostly, only seldom (if at all) touched code only called on errors is affected. Not everything changed below is "bad" - this PR also fixes a few issues with potential memory leaks.

Most important is a fix preventing a possible crash when upgrading an old double-hashed v5 password to a the BALLOON based v6 password format.

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Related issue or feature (if applicable): #2035

Pull request in docs with documentation (if applicable): N/A

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2. I have commented my proposed changes within the code.
3. I am willing to help maintain this change if there are issues with it later.
4. It is compatible with the EUPL 1.2 license
5. I have squashed any insignificant commits. (git rebase)

Checklist:

• The code change is tested and works locally.
• I based my code and PRs against the repositories developmental branch.
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• I have read the above and my PR is ready for review.

[yubiuser]

Superseded by #2059