HiveSigner integration

Description

Login and perform operations with HiveSigner.

For more details, please refer to https://peakd.com/hive-139531/@good-karma/imagehoster-hivesigner-and-condenser-bounty#@roomservice/re-good-karma-qd5qsb

The Merge Request contains almost the same change as condenser!74 (merged), except some minor differences.

Relevant Issues

Fixes: condenser#43 (closed)

src/app/components/cards/TransferHistoryRow/style.scss

 .Memo--badActor,
-.Memo--fromNegativeRepUser {
+.Memo--fromNegativeRepUser,
+.Memo--noPermission {
   .bad-actor-caution,
-  .from-negative-rep-user-caution {
+  .from-negative-rep-user-caution,
+  .no-permission-caution {
     color: darken($color-red, 10%);
     font-size: 75%;
     font-weight: bold;
@@ -9,7 +11,8 @@
     letter-spacing: 1px;
   }
   .bad-actor-explained,
-  .from-negative-rep-user-explained {
+  .from-negative-rep-user-explained,
+  .no-permission-explained {
     opacity: .5;
     font-size: 75%;
     max-width: 30em;