Implement support for 0.4 specification

[sdelatorrep]

Update the Elixir reference implementation so 0.4 version of the spec is supported. This includes support for structural variants, range queries and Consent Codes (we are not including ADA-M in this first release).

[sdelatorrep]

Changes applied in new branch v0.4. They include upgrading the Spring Boot version and implementing support for v0.4.

[sdelatorrep]

Some issues detected in the VCF parser provided with the reference implementation:

• VCF field AC should be used for the variantCount field in DatasetAlleleResponse.
• VCF field AN should be used for the callCount field in DatasetAlleleResponse.
• VCF field AF should be used for the frequencyfield in DatasetAlleleResponse.

From the VCF specification:

AN : total number of alleles in called genotypes AC : allele count in genotypes, for each ALT allele, in the same order as listed AF : allele frequency for each ALT allele in the same order as listed: use this when estimated from primary data, not called genotypes