Function: migrateToNewVault()

This allows a user to migrate to a new vault.

Branches and code coverage

Intended branches

• Mint new shares to the receiver. Handled in the deposit call with the new user as a parameter.

  Test coverage

• Burn the shares of the current vault for the caller.

  Test coverage

• Deposit the amount of tokens in the new vault.

  Test coverage

Negative behavior

• Should not allow user migrating if there is no migration vault set.

  Negative test