Merchant accounts updates

[tl-luca-baggi]

• removed currency from merchant account update sweeping request
• add metadata to merchant account transactions
• update version

Description

This PR is related to the following Jira tickets:

• ACL-186
• ACL-214

Changes

• add metadata optional property to merchant account transactions (refunds, payouts and merchant account payments)
• ⚠️ breaking: removed currency from update sweeping request

Type of change

Please select multiple options if required.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code where necessary
• I have added tests that prove my fix is effective or that my feature works
• I have updated the relevant documentation

[tl-luca-baggi]

removing currency property from update sweeping request is a breaking change