fix!: assemble of Transfer operation

[Torres-ssf]

• Close: Investigate bug on getTransferOperations #1774
• Close: Improve Variable Outputs documentation page #925

Some details about this PR

1. Since we already have the OperationName.transfer, I've removed the OperationName.contractTransfer.

   I reckon that we do not need yet another transfer-related operation.

   The Operation object has the from and to properties and each one has a property named type, which can be Account or Contract.

2. We can simplify transfers in 4 types:

   1. Account to Account - No receipts are generated since no opcodes are called.
   2. Account to Contract - Produces a Transfer receipt.
   3. Contract to Account - Produces a TransferOut receipt.
   4. Contract to Contract - Produces a Transfer receipt.

   This means that the TransferOperation needs to mainly be extracted from Transfer and TransferOut receipts, which was not the case until now.

3. I've removed the unit tests related to the TransferOperation and replaced them with e2e tests.

   Unit tests involve moving many pieces around and when you find yourself wasting hours creating mocks to cover many specific edge cases, it's because something is wrong.

   Often, these mocks are constructed based on the existing code, which can lead to misleading positive results if the code is wrong. (which was the case until now).

   So I am testing this with e2e tests since it takes fewer steps to simulate each case and we can have more confidence in the test results.

[Dhaiwat10]

First pass - great work!

[Dhaiwat10]

Awesome job @Torres-ssf 👏🏻

Really like the new e2e tests.

[arboleya]

Hell of a PR! 🔥

Perhaps we could merge #1801 here.

[github-actions]

Coverage Report:

Lines	Branches	Functions	Statements
79.42%(-0.04%)	70.17%(-0.15%)	77.9%(-0.02%)	79.5%(-0.04%)

Changed Files:

Ok	File (✨=New File)	Lines	Branches	Functions	Statements
🔴	packages/account/src/providers/transaction-summary/operations.ts	96.33% (-1.85%)	74.54% (-6.59%)	92.1% (-2.18%)	94.91% (-2.48%)