Clean up FarmIdByName storage

[renauter]

(1) FarmIdByName storage map should not reference ids of not existing farms

Seen on devnet:

Farm named x with id 15 is none

(2) Farm name keys in FarmIdByName storage map should match the name stored in farm

Seen on testnet:

In FarmIdByName storage map, key GCQ2W3EPMX4A3YI4KTQCXMXP7SFP4AW52LKCLACW32Y5S27EE6A6QHUL gives farm id 95 which name is GCQ2W3EPMX4A3YI4KTQCXMXP7SFP4AW52LKCLACW