Update Golang to 1.18

[TheRealSpaceShip]

To be in touch with the latest changes in Golang and to avoid a huge amount of changes in the future we need to update Golang to 1.18.
The new version of Golang introduces a new language feature - generics. We could use it to improve the codebase of Hub CLI in the future. As for today, we could start to use a cool library https://github.com/samber/lo which is a Lodash-style Go library based on Go 1.18+ Generics. This library could replace the main part of the util package which is not covered by unit tests.
Also as part of this update, we need to get rid of the go-bindata tool because it doesn't support anymore and Golang has the native support of Embedded Files in the core library since version 1.16.