rename binary from fetch to akai-fetch

Consistent with go.mod, usage strings, and docs.
Updated Dockerfile, electron config, and Makefile.

electron/package.json

@@ -16,8 +16,8 @@
     ],
     "extraResources": [
       {
-        "from": "../fetch",
-        "to": "fetch"
+        "from": "../akai-fetch",
+        "to": "akai-fetch"
       },
       {
         "from": "../scripts/extract_wavs.sh",
@@ -35,8 +35,8 @@
       "artifactName": "${name}-${version}-${arch}.${ext}",
       "extraResources": [
         {
-          "from": "../fetch",
-          "to": "fetch"
+          "from": "../akai-fetch",
+          "to": "akai-fetch"
         },
         {
           "from": "../scripts/extract_wavs.sh",