add validator: StringRuneCountBetween() and StringBytesBetween() instead StringLenBetween()

[ryodocx]

Summary

• In this PullRequest, add validator in order to count string length correctly.
• Current, StringLenBetween() count byte length.
• For example Japanese, 1 character mean 2 bytes.
  • Sometimes, improper validation implements in terraform-provider via this behavior

What's changes?

• add StringRuneCountBetween() for count string length
• add StringBytesBetween() for count byte length (it's just copy of StringLenBetween())
• add validation for parameters(min, max)
• add test

Related issues

• action.fixed_response.message_body in aws_lb_listener_rule is validated not by length, but by bytes hashicorp/terraform-provider-aws#19846
• ELBv2 FixedResponse with message_body (<= 1024 chars && > 1024bytes) cannot be registered  hashicorp/terraform-provider-aws#22949

---

test viewpoint

テスト観点メモ

• 型
  • string型: OK
  • string以外の型: NG
• 閾値の数値
  • 負数: NG
  • 0: OK
  • 正数: OK
• 閾値の関係
  • Min = Max: OK
  • Min < Max: OK
  • Min > Max: NG
• 閾値(Min)
  • 文字数(Byte数)より小さい: OK
  • 文字数(Byte数)と同じ: OK
  • 文字数(Byte数)より大きい: NG
• 閾値(Max)
  • 文字数(Byte数)より小さい: NG
  • 文字数(Byte数)と同じ: OK
  • 文字数(Byte数)より大きい: OK
• 文字種
  • シングルバイト文字(ASCII)
    • 空白
    • 制御文字
    • 図形文字(通常文字)
  • 2バイト文字
  • 3バイト文字
  • 4バイト文字

[ryodocx]

move to: hashicorp#985