Define context for scoped operation across core types

It holds necessary state plus additional information relative to the
context which we are being run to (e.g. if we are in a terminal or not).
Besides in the future we can use it also as a contextual logger to
provide more smart logging capabilities.

This also replace the general global configuration instance that
previously was share between the core components.

cmd/util/search.go

@@ -0,0 +1,42 @@
+// Copyright © 2021 Ettore Di Giacinto <mudler@mocaccino.org>
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program; if not, see <http://www.gnu.org/licenses/>.
+
+package util
+
+import "github.com/pterm/pterm"
+
+type TableWriter struct {
+	td pterm.TableData
+}
+
+func (l *TableWriter) AppendRow(item []string) {
+	l.td = append(l.td, item)
+}
+
+func (l *TableWriter) Render() {
+	pterm.DefaultTable.WithHasHeader().WithData(l.td).Render()
+}
+
+type ListWriter struct {
+	bb []pterm.BulletListItem
+}
+
+func (l *ListWriter) AppendItem(item pterm.BulletListItem) {
+	l.bb = append(l.bb, item)
+}
+
+func (l *ListWriter) Render() {
+	pterm.DefaultBulletList.WithItems(l.bb).Render()
+}