feat(web): validate password

[WaterLemons2k]

What does this PR do?

Use go-password-validator to checks that the password meets the minimum password requirements.

Fixes #778.

Motivation

#778

Additional Notes

https://github.com/wagslane/go-password-validator
https://github.com/coder/coder/blob/0c73164f15da870f0c71d842844a95e4fb73304e/coderd/userpassword/userpassword.go#L128

Known issue: After upgrading from a version that does not validate passwords, weak passwords may not be saved even if the password remains the same.

Solution:

-	// 如果密码不为空则检查是否够强
-	if passwordNew != "" {
+	// 如果更改了密码且不为空则检查是否够强
+	if conf.Password != passwordNew && passwordNew != "" {

[WaterLemons2k]

另外，目前如果密码不够强返回的错误说明是英文的，要不要基于 passwordvalidator.Validate() 修改以返回中文错误说明？

[jeessy2]

可以返回中文。minEntropy 60得不得高了点，选个适中的

[jeessy2]

thanks @WaterLemons2k