TokenEscrow

Description

This PR aims to:

• Add support for the TokenEscrow amendment (XLS-85).
• Fix the Flatten function for the Destination and Owner fields in the Escrow transaction types.
• Adds example of the TokenEscrow with an IOU.
• Adds a method to get the Sequence from the TxResponse which makes parsing easier for Escrows than response["Sequence"].

Type of change

• Bug fix
• New feature
• Breaking change
• Documentation update
• Refactoring

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 needed
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective
• New and existing unit tests pass locally with my changes

Changes

See description

Notes (optional)

Examples working: