[Clang-18] Encoder clang18 warnings

Basic info

• Float reference:
  • Encoder (float):
  • Decoder (float):
• Fixed point:
  • Encoder (fixed): 449b92ed
  • Decoder (fixed):

Bug description

Some warning discovered while running stereo encoder at different bit rates

• in IVAS_cpe_enc_fx, variables q_band_energies_LR and q_lf_E are passed to a function without being initialized
• in ivas_core_enc_fx, voice_factors_fx is passed to a function without being initialized
• in ext_sig_ana_fx.c, uninitialized part of mdstWin is copy to another vector
• in AVQ_cod_lpc_fx(), I16 is passed to a function without being initialized

Ways to reproduce

Box folder: ...\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-xxxx

compile with CLANG=1
Run the encoder at 256 kbps and 24.4 kbps