[Sonic Frontiers] Converse: fix OOB reads, use-after-free and memory leak

[hyperbx]

This PR addresses three critical issues in the hook initialised by the Converse library.

1. The string redirector was storing the length of the string data as the character length, rather than the number of characters in the string. This could lead to out-of-bounds reads when the game copies the redirected string into the Converse buffer.
2. The string redirector was freeing redirected strings before they were being used.
3. The string redirector could possibly return null. If it did, a new blank string would be allocated, but also never freed.

This fix needs testing on Linux, as these issues were made more apparent there, but these flaws would also affect Windows too.

[RagdollClash]

Fixes blank strings under Linux

[Mefiresu]

Unfortunately still seems to crash with the Tutorial Skip code for me...

[hyperbx]

Unfortunately still seems to crash with the Tutorial Skip code for me...

I've been able to replicate this on Windows and it does appear to be a fault with the Converse library. Looking into it.

[hyperbx]

@Mefiresu Tutorial Skip should work now, please test again using the latest Converse.hmm in the PR.

[Mefiresu]

Looks to be behaving properly now, 5/5 runs with no crashes.
Thanks for the patch!

[Sajidur78]

LGTM