Pull request: home: imp whois parse

Updates #2646.

Squashed commit of the following:

commit 0a5ff6ae74c532a296c0594a598a99c7cfaccf8c
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu May 20 14:07:08 2021 +0300

    home: imp code

commit 2af0f463a77b81e827d9faca079a19c5437e1cd9
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu May 20 13:48:08 2021 +0300

    home: imp whois parse

internal/home/whois_test.go

@@ -76,3 +76,77 @@ func TestWhois(t *testing.T) {
 	assert.Equal(t, "Imagiland", m["country"])
 	assert.Equal(t, "Nonreal", m["city"])
 }
+
+func TestWhoisParse(t *testing.T) {
+	const (
+		city    = "Nonreal"
+		country = "Imagiland"
+		orgname = "FakeOrgLLC"
+		whois   = "whois.example.net"
+	)
+
+	testCases := []struct {
+		want strmap
+		name string
+		in   string
+	}{{
+		want: strmap{},
+		name: "empty",
+		in:   ``,
+	}, {
+		want: strmap{},
+		name: "comments",
+		in:   "%\n#",
+	}, {
+		want: strmap{},
+		name: "no_colon",
+		in:   "city",
+	}, {
+		want: strmap{},
+		name: "no_value",
+		in:   "city:",
+	}, {
+		want: strmap{"city": city},
+		name: "city",
+		in:   `city: ` + city,
+	}, {
+		want: strmap{"country": country},
+		name: "country",
+		in:   `country: ` + country,
+	}, {
+		want: strmap{"orgname": orgname},
+		name: "orgname",
+		in:   `orgname: ` + orgname,
+	}, {
+		want: strmap{"orgname": orgname},
+		name: "orgname_hyphen",
+		in:   `org-name: ` + orgname,
+	}, {
+		want: strmap{"orgname": orgname},
+		name: "orgname_descr",
+		in:   `descr: ` + orgname,
+	}, {
+		want: strmap{"orgname": orgname},
+		name: "orgname_netname",
+		in:   `netname: ` + orgname,
+	}, {
+		want: strmap{"whois": whois},
+		name: "whois",
+		in:   `whois: ` + whois,
+	}, {
+		want: strmap{"whois": whois},
+		name: "referralserver",
+		in:   `referralserver: whois://` + whois,
+	}, {
+		want: strmap{},
+		name: "other",
+		in:   `other: value`,
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := whoisParse(tc.in)
+			assert.Equal(t, tc.want, got)
+		})
+	}
+}