cherry-pick: home: show version in install api

Closes #4026.

Squashed commit of the following:

commit bcd1315a10e819daee3aee323427d90a27860b4a
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Jan 18 14:57:49 2022 +0300

    openapi: fix example

commit b56e27c5ac1fc7c3f595057d77607479d72ec50a
Author: Ildar Kamalov <ik@adguard.com>
Date:   Tue Jan 18 14:55:51 2022 +0300

    client: show version on install page

commit 95dfbfaa1235deef7b55e51457d11c677f6ef6b5
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Jan 18 14:29:08 2022 +0300

    home: show version in install api

internal/version/version.go

@@ -62,18 +62,10 @@ func Version() (v string) {
 	return version
 }
 
-// Common formatting constants.
-const (
-	sp   = " "
-	nl   = "\n"
-	tb   = "\t"
-	nltb = nl + tb
-)
-
 // Constants defining the format of module information string.
 const (
 	modInfoAtSep    = "@"
-	modInfoDevSep   = sp
+	modInfoDevSep   = " "
 	modInfoSumLeft  = " (sum: "
 	modInfoSumRight = ")"
 )
@@ -142,6 +134,7 @@ const (
 func Verbose() (v string) {
 	b := &strings.Builder{}
 
+	const nl = "\n"
 	stringutil.WriteToBuilder(
 		b,
 		vFmtAGHHdr,
@@ -178,7 +171,7 @@ func Verbose() (v string) {
 	stringutil.WriteToBuilder(b, nl, vFmtDepsHdr)
 	for _, dep := range info.Deps {
 		if depStr := fmtModule(dep); depStr != "" {
-			stringutil.WriteToBuilder(b, nltb, depStr)
+			stringutil.WriteToBuilder(b, "\n\t", depStr)
 		}
 	}