Port MR2180 from float - Cleanup 20250715

Basic Info

• Original merge request in float repo: ivas-codec-pc/ivas-codec!2180 (merged)

Acceptance of

• FIX_938_COMPILER_WARNING /* FhG: Fix compiler warning in ivas_mdct_core_reconstruct() */
• FIX_1288_SPLIT_REND_XSAN /* Dlb: Fix asan, msan and usan issues in split rendering mode*/
• NONBE_FIX_1337_MISSING_DIRECTIVITY_DISTATT_EXTREND /* Eri: issue 1337: Missing directivity setting and distance attenuation in external renderer IVAS_rend */ -> cleaned out with !2178 (merged) / !2180 (merged)
• NONBE_1329_FIX_OSBA_CRASH /* FhG: issue 1329: prevent assert when bit budget is low*/ -> cleaned out with !2178 (merged) / !2180 (merged)

Note: thick box indicates whether the switch was already ported