Change links to TAIR

[pgaudet]

From Leonore:

Linking using AGI locus ID
The base URL for linking is:
https://www.arabidopsis.org/locus?name=
e.g. https://www.arabidopsis.org/locus?name=AT1G75410

@kltm @alexsign

[kltm]

@pgaudet I want to make sure we contextualize this with #2537 .