Implement initial framework for Dolphin importer

- Uses cache reading code from Lutris by strycore. https://github.com/lutris/lutris/blob/master/lutris/util/dolphin/cache_reader.py#L23

src/importer/sources/dolphin_source.py

@@ -0,0 +1,82 @@
+# dolphin_source.py
+#
+# Copyright 2023 Rilic
+#
+# 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 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 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/>.
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from time import time
+
+from src import shared
+from src.game import Game
+from src.importer.sources.location import Location
+from src.importer.sources.source import Source, SourceIterationResult, SourceIterator
+from src.utils.dolphin_cache_reader import DolphinCacheReader
+
+
+class DolphinIterator(SourceIterator):
+    source: "DolphinSource"
+
+    def generator_builder(self) -> SourceIterationResult:
+        added_time = int(time())
+
+        cache_reader = DolphinCacheReader(self.source.cache_location["cache_file"])
+        games_data = cache_reader.get_games()
+
+        for game_data in games_data:
+            print(game_data["file_name"])
+
+            # Build game
+            game = Game(values)
+            values = {
+                "source": self.source.id,
+                "added": added_time,
+                #    "name": item["label"],
+                #    "game_id": self.source.game_id_format.format(game_id=game_id),
+                #    "executable": self.source.executable_format.format(
+                #        rom_path=item["path"],
+                #        core_path=core_path,
+                #    ),
+            }
+
+            game = Game(values)
+            additional_data = {}
+
+            yield (game, additional_data)
+
+
+class DolphinSource(Source):
+    name = "Dolphin"
+    available_on = {"linux"}
+    iterator_class = DolphinIterator
+
+    cache_location = Location(
+        schema_key="dolphin-cache-location",
+        candidates=(
+            shared.flatpak_dir / "org.DolphinEmu.dolphin-emu" / "cache" / "dolphin-emu",
+            shared.home / ".cache" / "dolphin-emu",
+        ),
+        paths={
+            "cache_file": (False, "gamelist.cache"),
+        },
+    )
+
+    @property
+    def executable_format(self):
+        self.config_location.resolve()
+        is_flatpak = self.data_location.root.is_relative_to(shared.flatpak_dir)
+        base = "flatpak run org.DolphinEmu.dolphin-emu" if is_flatpak else "dolphin-emu"
+        args = '-e "{rom_path}"'
+        return f"{base} {args}"