Includes mmctl into the mono-repo (#23091)

* Includes mmctl into the mono-repo

* Update to use the new public module paths

* Adds docs check to the mmctl CI

* Fix public utils import path

* Tidy up modules

* Fix linter

* Update CI tasks to use the new file structure

* Update CI references

server/cmd/mmctl/commands/importer/utils.go

@@ -0,0 +1,66 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package importer
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+)
+
+type ImportFileInfo struct {
+	Source      string `json:"archive_name"`
+	FileName    string `json:"file_name,omitempty"`
+	CurrentLine uint64 `json:"current_line,omitempty"`
+	TotalLines  uint64 `json:"total_lines,omitempty"`
+}
+
+type ImportValidationError struct { //nolint:govet
+	ImportFileInfo
+	FieldName       string
+	Err             error
+	Suggestion      string
+	SuggestedValues []any
+	ApplySuggestion func(any) error
+}
+
+func (e *ImportValidationError) MarshalJSON() ([]byte, error) {
+	t := struct { //nolint:govet
+		ImportFileInfo
+		FieldName       string `json:"field_name,omitempty"`
+		Err             string `json:"error,omitempty"`
+		Suggestion      string `json:"suggestion,omitempty"`
+		SuggestedValues []any  `json:"suggested_values,omitempty"`
+	}{
+		ImportFileInfo:  e.ImportFileInfo,
+		FieldName:       e.FieldName,
+		Suggestion:      e.Suggestion,
+		SuggestedValues: e.SuggestedValues,
+	}
+
+	if e.Err != nil {
+		t.Err = e.Err.Error()
+	}
+
+	return json.Marshal(t)
+}
+
+func (e *ImportValidationError) Error() string {
+	msg := &strings.Builder{}
+	msg.WriteString("import validation error")
+
+	if e.FileName != "" || e.Source != "" {
+		fmt.Fprintf(msg, " in %s->%s:%d", e.Source, e.FileName, e.CurrentLine)
+	}
+
+	if e.FieldName != "" {
+		fmt.Fprintf(msg, " field %q", e.FieldName)
+	}
+
+	if e.Err != nil {
+		fmt.Fprintf(msg, ": %s", e.Err)
+	}
+
+	return msg.String()
+}