feat(tracker): add a preset explorer with search and filters

Closes #91

tracker/presets/WND/Pan_flute.yml

@@ -0,0 +1,38 @@
+numvoices: 2
+units:
+    - id: 1209
+      parameters: {}
+      comment: Oscillators
+    - type: oscillator
+      id: 1201
+      parameters: {color: 128, detune: 64, gain: 128, looplength: 42, loopstart: 1800, phase: 0, samplestart: 255133, shape: 64, stereo: 0, transpose: 64, type: 4}
+    - type: oscillator
+      id: 1202
+      parameters: {color: 128, detune: 69, gain: 64, looplength: 1645, loopstart: 3820, phase: 0, samplestart: 551786, shape: 53, stereo: 0, transpose: 83, type: 4}
+    - type: addp
+      id: 1203
+      parameters: {stereo: 0}
+    - type: oscillator
+      id: 1204
+      parameters: {color: 76, detune: 64, gain: 71, phase: 0, shape: 64, stereo: 0, transpose: 76, type: 1, unison: 0}
+    - type: addp
+      id: 1205
+      parameters: {stereo: 0}
+    - id: 1210
+      parameters: {}
+      comment: Main envelope
+    - type: envelope
+      id: 1200
+      parameters: {attack: 33, decay: 104, gain: 64, release: 64, stereo: 0, sustain: 64}
+    - type: mulp
+      id: 1206
+      parameters: {stereo: 0}
+    - id: 1211
+      parameters: {}
+      comment: Pan & output
+    - type: pan
+      id: 1207
+      parameters: {panning: 64, stereo: 0}
+    - type: outaux
+      id: 1208
+      parameters: {auxgain: 33, outgain: 40, stereo: 1}