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

Closes #91

tracker/presets/GTR/Guitar_2.yml

@@ -0,0 +1,36 @@
+numvoices: 1
+units:
+    - id: 87
+      parameters: {}
+      comment: Karplus-Strong
+    - type: envelope
+      id: 2
+      parameters: {attack: 0, decay: 58, gain: 83, release: 0, stereo: 0, sustain: 0}
+    - type: noise
+      id: 3
+      parameters: {gain: 64, shape: 127, stereo: 0}
+    - type: mulp
+      id: 4
+      parameters: {stereo: 0}
+    - type: delay
+      id: 6
+      parameters: {damp: 16, dry: 128, feedback: 128, notetracking: 1, pregain: 128, stereo: 0}
+      varargs: [10787]
+    - id: 88
+      parameters: {}
+      comment: Main envelope
+    - type: envelope
+      id: 1
+      parameters: {attack: 0, decay: 0, gain: 64, release: 72, stereo: 0, sustain: 128}
+    - type: mulp
+      id: 85
+      parameters: {stereo: 0}
+    - id: 89
+      parameters: {}
+      comment: Output
+    - type: pan
+      id: 86
+      parameters: {panning: 64, stereo: 0}
+    - type: outaux
+      id: 10
+      parameters: {auxgain: 16, outgain: 36, stereo: 1}