[FEATURE] add localisation support for any HTML template served through HyperSwitch

[kashif-m]

Feature Description

Specifically for payout links

The terminal status pages for payout links are served from backend with basic HTML / JS / CSS templates. The language used in these resources is English which is hardcoded. There needs to be a locale support for handling localisation of payout links.

Possible Implementation

Provisioning of locales

• make use of rust-i18n for maintaining locales in the server
• make use of t! macro for reading the locales at runtime

Consumption in payout links

• Consume locale during payout creation and store the payout link's URL with a hardcoded locale as a query parameter
• Fetch locale during render request and pass to the request handler
• Inject the string data dynamically into HTML / JS resources based on the locale
• Inject locale in SDK for SDK localisation

Have you spent some time checking if this feature request has been raised before?

• [X] I checked and didn't find a similar issue

Have you read the Contributing Guidelines?

• [X] I have read the Contributing Guidelines

Are you willing to submit a PR?

Yes, I am willing to submit a PR!