fix(sdk-coin-xrp): set SendMax to cover MPT TransferFee on withdrawal

[0xPrabh]

Description

Fixes broken withdrawal flow for XRP MPT tokens that have a non-zero TransferFee on their MPTokenIssuance ledger object (e.g. txrp:feesec).

Root cause: When an MPT issuance has TransferFee > 0, rippled deducts Amount + ⌈Amount × fee / 100_000⌉ from the sender. Without SendMax set, the transaction fails with tecPATH_PARTIAL.

Fix:

• Added transferFee(fee: number) method to MPTokenTransferBuilder that accepts the MPTokenIssuance.TransferFee ledger field (integer in [0, 50_000])
• Computes SendMax = Amount + ⌈Amount × fee / 100_000⌉ using ceiling division (BigInt)
• Restores SendMax across the multi-sig rebuild round-trip so a second signer doesn't lose it

Issue Number: CHALO-802

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Added unit tests covering:

• SendMax set correctly when transferFee is non-zero (0.1% fee on 1,000,000 → SendMax = 1,001,000)
• Ceiling division for fractional fees (1 unit × 0.1% → fee rounds up to 1)
• SendMax preserved through serialize → rebuild round-trip (multi-sig path)
• transferFee(0) omits SendMax
• Rejects invalid fee values (negative, > 50,000, non-integer)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• My commits follow Conventional Commits
• The ticket was included in the commit message (CHALO-802)
• I have added tests that prove my fix is effective
• New and existing unit tests pass locally

[linear-code]

CHALO-802