[skip-changelog] Added more lint checks and fixed some warnings. (#2610)

* Enabled more checks in golangci-lint

* Removed unreachable code (impossible condition detected by linter)

internal/arduino/sketch/sketch.go:108:14: nilness: impossible condition: non-nil == nil (govet)
        if mainFile == nil {
                    ^

* Removed function alias for i18n.Tr

This allows a deeper lint-check of printf style functions, like:

  commands/instances.go:344:46: printf: github.com/arduino/arduino-cli/internal/i18n.Tr format %v reads arg #1, but call has 0 args (govet)
		s := status.Newf(codes.FailedPrecondition, i18n.Tr("Loading index file: %v"), err)

* Fixed a lot of i18n.Tr formatting errors

This commit fixes invalid calls to i18n.Tr.

1. Missing positional arguments, for example:

  return fmt.Errorf(i18n.Tr("installing %[1]s tool: %[2]s"), tool, err)

in the above case the positional arguments must be part of the Tr call:

-    return fmt.Errorf(i18n.Tr("installing %[1]s tool: %[2]s"), tool, err)
+    return fmt.Errorf(i18n.Tr("installing %[1]s tool: %[2]s", tool, err))

2. This also makes the fmt.Errorf call useless and it could be replaced by
the less expensive errors.New:

-    return fmt.Errorf(i18n.Tr("installing %[1]s tool: %[2]s", tool, err))
+    return errors.New(i18n.Tr("installing %[1]s tool: %[2]s", tool, err))

but we have cases of useless calls even when the string is a constant,
for example:

-    err := fmt.Errorf(i18n.Tr("no instance specified"))
+    err := errors.New(i18n.Tr("no instance specified"))

Unfortunately, this imperfection is not detected by the linter.

3. The "%w" directive is not supported directly in i18n.Tr, so we have
   to wrap it around another fmt.Errorf:

-    return nil, fmt.Errorf(i18n.Tr("reading library headers: %w"), err)
+    return nil, fmt.Errorf("%s: %w", i18n.Tr("reading library headers"), err)

* Removed useless call to i18n.Tr

.golangci.yml

@@ -33,6 +33,51 @@ linters:
     #- protogetter
 
 linters-settings:
+  govet:
+    # Enable analyzers by name.
+    # Run `GL_DEBUG=govet golangci-lint run --enable=govet` to see default, all available analyzers, and enabled analyzers.
+    enable:
+      - appends
+      - asmdecl
+      - assign
+      - atomic
+      - atomicalign
+      - bools
+      - buildtag
+      - cgocall
+      - composites
+      - copylocks
+      - deepequalerrors
+      - defers
+      - directive
+      - errorsas
+      #- fieldalignment
+      - findcall
+      - framepointer
+      - httpresponse
+      - ifaceassert
+      - loopclosure
+      - lostcancel
+      - nilfunc
+      - nilness
+      - printf
+      - reflectvaluecompare
+      #- shadow
+      - shift
+      - sigchanyzer
+      - slog
+      - sortslice
+      - stdmethods
+      - stringintconv
+      - structtag
+      - testinggoroutine
+      - tests
+      - unmarshal
+      - unreachable
+      - unsafeptr
+      - unusedresult
+      - unusedwrite
+
   forbidigo:
     forbid:
       - p: ^(fmt\.Print(|f|ln)|print|println)$