Improve prompts for link command

[verythorough]

Summary

Restores the site name search functionality removed in #335, along with some minor updates to copy and code. Partially addresses #496.

Test plan

Run the netlify link command and try all of the options in the prompt tree:

• Use Git remote
  • with no origin set in git remote (prompt won't display in choices)
  • with an origin set that has no connected sites
  • with an origin set that has one connected site (this may still fail due to netlify link doesn't recognize sites in different teams #498 and Support pagination js-client#39)
  • with an origin set that has more than one connected site (may also fail for same reasons)
  • from an account with no sites
• Search by name
  • with a string of garbage text that you know won't match anything
  • with a unique site name that isn't also part of another site name
  • with a short string that you know will match multiple site names
  • with an empty input
  • from an account with no sites
• Choose from a list of sites
  • from an account with multiple sites
  • from an account with no sites
• Enter site ID
  • with a valid site ID
  • with an invalid site ID

Description for the changelog

• Restore site name search functionality in link command prompts
• Update link command prompt text for greater clarity and consistency
• Refactor link command prompt code for consistency between prompts

Other impacts

This also changes the telemetry data collected for the kind field:

• byName changed to refer to the "search by name" prompt again as it did in v2.11.23 and before
• "Choose from list" prompt is now referred to as fromList

A picture of a cute animal (not mandatory but encouraged)

[RaeesBhatti]

Tested and everything seems to be working. Thanks @verythorough 👍🏽