Remove DF2XSS

[cstirdivant]

DF2XSS is a duplicate of DFSS2X

• remove DF2XSS as it does not match naming precedent
• update all canonicals that implement DF2XSS to use DFSS2X instead

[cstirdivant]

Ramifications of this change:

Affects the following canonical and non-canonical types:

• FCU_DF2XSS_DSP_DXZC (implemented by four entities)
• FCU_DF2XSS_DSP_DXZC_NONCANONICAL_1 (implemented by zero entities)
• FCU_DF2XSS_RTC_DXRC (implemented by zero entities)
• FCU_DF2XSS_RTC_DXRC_NONCANONICAL_1 (implemented by zero entities)
• FCU_DF2XSS_RTC_DXRC_NONCANONICAL_2 (implemented by zero entities)
• MAU_DF2XSS_DFVSC2X_DSP_HTZC (implemented by zero entities)
• MAU_DF2XSS_DFVSC2X_HP2ZC_HTZC_OAFC (implemented by zero entities)

Suggested next steps:

• Delete DF2XSS from the abstracts
• For all canonical types affected, replace DF2XSS with DFSS2X
• For all non-canonical types, remove them entirely (since they are not implemented by any entities, and are non-canonical)
• For FCU_DF2XSS_DSP_DXZC, evaluate the lift to re-map the necessary fan fields to align with DFSS2X