When using the authentication_ldap_simple plugin, the ldap query is not properly escaped, when the users DN has a double quote `"` in their name.

During authentication, the function "search_ldap_uid" returns the users DN.

After authentication, in order to proxy the user to a domain group, the function "[search_groups|https://github.com/percona/percona-server/blob/8.0/plugin/auth_ldap/src/connection.cc#L300]" is called, which looks for the group, and uses the users DN to filter the users groups (Replacing "{UD}" in the variable "authentication_ldap_simple_group_search_filter" with the users DN).

If the users DN contains a double quote, then the library will attempt to pass the string returned from `search_ldap_uid` to the ldap function `ldap_search_ext_s`, which will return an error: `Bad search filter`

The reason for this, is that the DN returned by `search_ldap_uid` is not properly escaped.

The ldap library expects double quotes to be double escaped (usern
"ame instead of usern\"ame), while it only returns singly escaped DN.

This means:

```

ldap_search_ext_s(filter_to_find_user_dn) == "CN=tea\\\"m,CN=Users,DC=example,DC=local"

```

where the query must be:

```

1. This will work

ldap_search_ext_s("CN=tea\\\\\"m,CN=Users,DC=example,DC=local")

1. This will not work

ldap_search_ext_s("CN=tea\\\"m,CN=Users,DC=example,DC=local")

```

As a fix, I am opening a PR on github, which will replace the string `\"` with `
"` in the user DN