feat(db): 添加对达梦数据库的支持

- 在应用程序中新增对达梦数据库（DM）的配置和连接支持
- 实现 SetDmDB 函数以配置达梦数据库连接
- 更新数据库操作逻辑，支持达梦特有的 SQL 语法和功能
- 在相关文件中添加达梦数据库的处理逻辑，包括表创建、数据插入和查询
- 更新 go.mod 和 go.sum 文件以引入达梦数据库驱动
- 增强文档，详细说明达梦数据库的配置和使用方法

vendor/golang.org/x/text/internal/stringset/set.go

@@ -0,0 +1,86 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package stringset provides a way to represent a collection of strings
+// compactly.
+package stringset
+
+import "sort"
+
+// A Set holds a collection of strings that can be looked up by an index number.
+type Set struct {
+	// These fields are exported to allow for code generation.
+
+	Data  string
+	Index []uint16
+}
+
+// Elem returns the string with index i. It panics if i is out of range.
+func (s *Set) Elem(i int) string {
+	return s.Data[s.Index[i]:s.Index[i+1]]
+}
+
+// Len returns the number of strings in the set.
+func (s *Set) Len() int {
+	return len(s.Index) - 1
+}
+
+// Search returns the index of the given string or -1 if it is not in the set.
+// The Set must have been created with strings in sorted order.
+func Search(s *Set, str string) int {
+	// TODO: optimize this if it gets used a lot.
+	n := len(s.Index) - 1
+	p := sort.Search(n, func(i int) bool {
+		return s.Elem(i) >= str
+	})
+	if p == n || str != s.Elem(p) {
+		return -1
+	}
+	return p
+}
+
+// A Builder constructs Sets.
+type Builder struct {
+	set   Set
+	index map[string]int
+}
+
+// NewBuilder returns a new and initialized Builder.
+func NewBuilder() *Builder {
+	return &Builder{
+		set: Set{
+			Index: []uint16{0},
+		},
+		index: map[string]int{},
+	}
+}
+
+// Set creates the set created so far.
+func (b *Builder) Set() Set {
+	return b.set
+}
+
+// Index returns the index for the given string, which must have been added
+// before.
+func (b *Builder) Index(s string) int {
+	return b.index[s]
+}
+
+// Add adds a string to the index. Strings that are added by a single Add will
+// be stored together, unless they match an existing string.
+func (b *Builder) Add(ss ...string) {
+	// First check if the string already exists.
+	for _, s := range ss {
+		if _, ok := b.index[s]; ok {
+			continue
+		}
+		b.index[s] = len(b.set.Index) - 1
+		b.set.Data += s
+		x := len(b.set.Data)
+		if x > 0xFFFF {
+			panic("Index too > 0xFFFF")
+		}
+		b.set.Index = append(b.set.Index, uint16(x))
+	}
+}