[Feature Request] Keybindings depending on the filetype

[raidenXR]

Keybindings depending on the filetype to have build actions and quickfix plugin work together nicely

Depending on the file type, it might be better to bind the same key to a different command.
I.e with quickfix, depending on the filetype the user might want to execute a different command.
I know about chaining commands with ,, |, &` but that's not the same thing.
The snippet below raises some error when running micro

"*.cs": {
    "F5": "command:fexec dotnet build",
    "Shift-F5": "command:fexec dotnet test",
    },
"*.zig": {
    "F5": "command:fexec zig build",
    "F7": "command:fexec zig ast-check {f}",
    "Shift-F5": "command:fexec zig test {f}",
},

Error

Micro encountered an error: runtime.errorString runtime error: invalid memory address or nil pointer dereference
/usr/lib/golang/src/runtime/panic.go:212 (0x55f1979d3273)
/usr/lib/golang/src/runtime/panic.go:211 (0x55f1979d30f3)
/builddir/build/BUILD/micro-2.0.8/_build/src/github.com/zyedidia/micro/internal/action/bindings.go:88 (0x55f197ed9cbf)
/builddir/build/BUILD/micro-2.0.8/_build/src/github.com/zyedidia/micro/internal/action/bindings.go:70 (0x55f197ed96d7)
/builddir/build/BUILD/micro-2.0.8/_build/src/github.com/zyedidia/micro/cmd/micro/micro.go:318 (0x55f197f15eea)
/usr/lib/golang/src/runtime/proc.go:204 (0x55f1979bfbe9)
/usr/lib/golang/src/runtime/asm_amd64.s:1374 (0x55f1979f34a1)

[raidenXR]

With chaining i.e

"F5": "command:fexec make|command:fexec dotnet build|command:fexec zig build",
"F7": "command:fexec zig ast-check {f}",
"Shift-F5": "command:fexec zig test {f}|command:fexec dotnet test"

things get really weird in case of the quickfix plugin, when binding build action is desired.
If it is possible to implement the alternative, then build actions would be much more straightforward

"*.cs": {
    "F5": "command:fexec dotnet build",
    "Shift-F5": "command:fexec dotnet test",
    },
"*.zig": {
    "F5": "command:fexec zig build",
    "F7": "command:fexec zig ast-check {f}",
    "Shift-F5": "command:fexec zig test {f}",
},

[serge-v]

you can bind your script "F5": "command:fexec do-action.sh {f} and do actions depending on the file type inside it. It is more flexible. For example, someday you may need to detect a file type by signature, not by extension.