Review usage of INFO.END

[cmdcolin]

The latest VCF 4.5 claims INFO.END is deprecated

 END: Deprecated. Retained for backwards compatibility with earlier versions of VCF and older VCF indexing
software which rely on this field being present.
This is a computed field that, when present, must be set to the maximum end reference position (1-based) of:
the position of the final base of the REF allele, the end position corresponding to the SVLEN of a symbolic
SV allele, and the end positions calculated from FORMAT LEN for the <*> symbolic allele.
The computed value of this field is used to compute BCF’s rlen field (see 6.3.1) and is important when indexing
VCF/BCF files to enable random access and querying by position

I am not sure if we 'rely' on it anywhere but there may be a need to be a review and switch to SVLEN or something like this