consistently apply env vars in CLI

[imogenkinsman]

see #16048 for a list of env vars we use.

We use viper.BindEnv to access env vars for the CLI tool, but it isn't used in all places where it should be.

Investigate where env vars aren't being used in our CLI and add support in those places.

• the tasks cli commands don't use env vars at all
• the users cli commands also don't use env vars
• possibly other places

[dearyhud]

did a quick ack around cmd and found these files not using viper.BindEnv in places where it should

cmd/influx/bucket.go
cmd/influx/authorization.go
cmd/influx/organization.go
cmd/influx/pkg.go
cmd/influx/setup.go

@jademcgough