Improve detection japanese region

[alexiglesias31]

Rel card: https://app.clickup.com/t/85zu3b9q8

Reported issue:

• City may be empty in the order (this depends if the customer inputs the city in the Amazon address, it's not required for JP)
• Last name filled with "." (this also depends if the user inputs the fullname without spaces, like テストアマゾン, "." is the fallback, since last name is required for WC compatibility purposes)

Proposed fix:

• Use "-" instead of "." as a filler
• Improve detection of the Prefecture, using the same snippet than Stripe

[alexiglesias31]

@lauramelos adding some new commits to fix the following issues:

• https://app.clickup.com/t/86dtchqkr
• https://app.clickup.com/t/86dtwrkaw
• https://app.clickup.com/t/86dth8a9m