[chore] ensure consistent caller name fetching regardless of compiler inlining (#3323)

* move logging levels into log package itself

* ensure inconsistent inlining doesn't mess with log calling function name

* remove unused global variable

* fix log level

internal/log/level.go

@@ -0,0 +1,38 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package log
+
+// LEVEL defines a level of logging.
+type LEVEL uint8
+
+// Default levels of logging.
+const (
+	UNSET LEVEL = 0
+	PANIC LEVEL = 1
+	ERROR LEVEL = 100
+	WARN  LEVEL = 150
+	INFO  LEVEL = 200
+	DEBUG LEVEL = 250
+	TRACE LEVEL = 254
+	ALL   LEVEL = ^LEVEL(0)
+)
+
+// CanLog returns whether an incoming log of 'lvl' can be logged against receiving level.
+func (loglvl LEVEL) CanLog(lvl LEVEL) bool {
+	return loglvl > lvl
+}