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

Closes #91

tracker/presets/KEYS/Pop_piano_2.yml

@@ -0,0 +1,32 @@
+numvoices: 4
+units:
+    - id: 1187
+      parameters: {}
+      comment: Oscillators
+    - type: oscillator
+      id: 2
+      parameters: {color: 64, detune: 64, gain: 96, looplength: 1487, loopstart: 8309, phase: 0, samplestart: 972709, shape: 64, stereo: 0, transpose: 68, type: 4, unison: 0}
+    - type: oscillator
+      id: 1241
+      parameters: {color: 64, detune: 67, gain: 96, looplength: 1339, loopstart: 9176, phase: 0, samplestart: 982589, shape: 64, stereo: 0, transpose: 72, type: 4}
+    - type: addp
+      id: 1185
+      parameters: {stereo: 0}
+    - id: 1188
+      parameters: {}
+      comment: Envelope
+    - type: envelope
+      id: 1
+      parameters: {attack: 0, decay: 79, gain: 64, release: 34, stereo: 0, sustain: 32}
+    - type: mulp
+      id: 1186
+      parameters: {stereo: 0}
+    - id: 1189
+      parameters: {}
+      comment: Pan & output
+    - type: pan
+      id: 5
+      parameters: {panning: 64, stereo: 0}
+    - type: outaux
+      id: 6
+      parameters: {auxgain: 45, outgain: 64, stereo: 1}