Feature: keep input order

[zx8754]

Below two queries return the same output:

LDmatrix(snps = c("chr13:32444611", "chr13:32509120"),
         pop = "EUR", r2d = "r2",
         token = LDLINK_TOKEN)
LDmatrix(snps = c("chr13:32509120", "chr13:32444611"),
         pop = "EUR", r2d = "r2",
         token = LDLINK_TOKEN)

#    RS_number rs496202 rs11147477
# 1   rs496202    1.000      0.202
# 2 rs11147477    0.202      1.000

This is fine when we supply rsids instead of positions, we could just match them up by rsid. But when we supply chr:pos, then it is not easy to map chr:pos to output.

Could we have an argument sort = TRUE/FALSE ?