Support and default to UUID for PostgreSQL uuid

[iamed2]

Closes #260

This adds binary format parsing for UUID and sets the default Julia type for PostgreSQL's uuid to Base.UUID. The import relies on the UUIDs stdlib export for stability's sake.

Array support was easy enough to add as well.

Open question on whether changing the default type away from the String fallback needs a major version update: https://discourse.julialang.org/t/anyone-fetching-uuids-using-libpq-jl/89395/3

I think if people conclude it does, I'll change to ensure this doesn't set the default but still supports the same operations when UUID is specified.

[github-actions]

[JuliaFormatter] _{reported by reviewdog 🐶}

Suggested change

	@testset "UUID" begin
	tests = (
	("'6dc2b682-a411-a51f-ce9e-af63d1ef7c1a'::uuid", UUID("6dc2b682-a411-a51f-ce9e-af63d1ef7c1a")),
	@testset "Parameters" begin
	conn = LibPQ.Connection(
	"dbname=postgres user=$DATABASE_USER"; throw_error=true

[github-actions]

[JuliaFormatter] _{reported by reviewdog 🐶}

Suggested change

	@testset for (pg_str, obj) in tests
	result = execute(conn, "SELECT $pg_str = \$1", [obj])
	@test first(first(result))
	close(result)
	@testset "UUID" begin
	tests = ((
	"'6dc2b682-a411-a51f-ce9e-af63d1ef7c1a'::uuid",
	UUID("6dc2b682-a411-a51f-ce9e-af63d1ef7c1a"),
	),)
	@testset for (pg_str, obj) in tests
	result = execute(conn, "SELECT $pg_str = \$1", [obj])
	@test first(first(result))
	close(result)
	end

[github-actions]

[JuliaFormatter] _{reported by reviewdog 🐶}

Suggested change

end

[robsmith11]

Seems to work well. Can it be merged?

[rofinn]

LGTM, reminder to bump the minor release. I'm inclined to holdoff on changing the String fallback for now. Might want to make an issue for it though?

[robsmith11]

Good to merge?

[rofinn]

No, this MR needs a rebase before we can proceed.

[robsmith11]

Rebased:
#288