refactor: commands runner (#42)

* feat(utils): first impl of own commands runner

* refactor(gotests): uses own runner instead of vendored

* refactor(utils): back to plenary.job

* refactor(gotests): use new runner, clean code

* fix(runner): now it returns output correctly

* refactor(iferr): use vim.system

i have tried to use _utils.runner, but i can't figure out how to make `< file.go` for the command

* refactor(impl): use new runner

* refactor(installer): use new runner

* refactor(struct_tags): use new runner

* refactor: commands such as :GoGet runs with new runner

* refactor: throw errors in more lua way, i think

* refactor(utils): notify now has title

* refactor: use more correct way of notifying

* refactor(runner): write error message on error

lua/gopher/init.lua

@@ -1,6 +1,6 @@
 local tags = require "gopher.struct_tags"
 local tests = require "gopher.gotests"
-local uc = require "gopher._utils.commands"
+local gocmd = require("gopher._utils.runner.gocmd").run
 local gopher = {}
 
 gopher.setup = require("gopher.config").setup
@@ -17,19 +17,19 @@ gopher.test_exported = tests.all_exported_tests
 gopher.tests_all = tests.all_tests
 
 gopher.get = function(...)
-  uc("get", ...)
+  gocmd("get", { ... })
 end
 
 gopher.mod = function(...)
-  uc("mod", ...)
+  gocmd("mod", { ... })
 end
 
 gopher.generate = function(...)
-  uc("generate", ...)
+  gocmd("generate", { ... })
 end
 
 gopher.work = function(...)
-  uc("work", ...)
+  gocmd("work", { ... })
 end
 
 return gopher