Add getPasswordAsChars and deprecate getPassword

[aarifkhan7]

feat: Add getPasswordAsChars() method to interface and class

• Introduced getPasswordAsChars() method in the relevant interface and Java class.
• This method provides a char[] alternative to the existing password retrieval mechanism.
• The goal is to progressively upgrade client classes to use this method for better security and memory management as discussed in DefaultJedisClientConfig password exposure issue #4021.

Further comments are appreciated! :)