refactor: improve return types of validate method

[rocktimsaikia]

1. Added function overloads to improve the return type of the verify class method specifically.

Before:

Used to return the same union type. Which required hacks like as string[] in TS.

validate("password") # Boolean | string[]
validate("password", { list: true }) # Boolean | string[]
validate("password", { details: true }) # Boolean | string[]

After:

Now returns single specific type depending on the options provieded. Better DX.

validate("password") # Boolean
validate("password", { list: true }) # string[]
validate("password", { details: true }) # IDetails[]

2. Defined proper interfaces (IOptions, IDetails) for options and details.

3. Other changes are just auto formatting by prettier plugin.