Nuget.org Sponsorship Feature (#10580)

* Added database migration for SponsorshipUrls column in PackageRegistrations table

* Created sponsor button and popup on package details page to display multiple sponsorship URLs 

* Added Manage sponsorship links section to manage package page to allow adding/removing sponsorship links

* Added manage sponsorship links button and view in admin panel for admin capability to add/remove sponsorship links

Author: pranathibora14

src/Bootstrap/dist/css/bootstrap-theme.css

@@ -36,6 +36,7 @@
 @import "page-reset-password.less";
 @import "page-search-sxs.less";
 @import "page-sign-in.less";
+@import "page-sponsorship-links.less";
 @import "page-statistics-most-downloaded.less";
 @import "page-statistics-overview.less";
 @import "page-statistics-per-package.less";

src/Bootstrap/less/theme/all.less

@@ -677,3 +677,15 @@ body[id="/"] {
     left: 0;
   }
 }
+
+.form-horizontal span.text-warning-brand {
+    color: var(--statusDangerForeground3Rest);
+    font-weight: bold;
+}
+
+.form-horizontal span.help-text-brand {
+    color: var(--neutralForeground2Rest);
+    font-size: 16px;
+    line-height: 2;
+    margin-top: 1.5rem;
+}