Introduce MPT support (XLS-33d): (#5143)

Amendment:
- MPTokensV1

New Transactions:
- MPTokenIssuanceCreate
- MPTokenIssuanceDestroy
- MPTokenIssuanceSet
- MPTokenAuthorize

Modified Transactions:
- Payment
- Clawback

New Objects:
- MPTokenIssuance
- MPToken

API updates:
- ledger_entry
- account_objects
- ledger_data

Other:
- Add += and -= operators to ValueProxy

Read full spec: https://github.com/XRPLF/XRPL-Standards/tree/master/XLS-0033d-multi-purpose-tokens

---------
Co-authored-by: Shawn Xie <shawnxie920@gmail.com>
Co-authored-by: Howard Hinnant <howard.hinnant@gmail.com>
Co-authored-by: Ed Hennis <ed@ripple.com>
Co-authored-by: John Freeman <jfreeman08@gmail.com>

include/xrpl/protocol/STBitString.h

@@ -84,6 +84,7 @@ private:
 
 using STUInt128 = STBitString<128>;
 using STUInt160 = STBitString<160>;
+using STUInt192 = STBitString<192>;
 using STUInt256 = STBitString<256>;
 
 template <int Bits>
@@ -136,6 +137,13 @@ STUInt160::getSType() const
     return STI_UINT160;
 }
 
+template <>
+inline SerializedTypeID
+STUInt192::getSType() const
+{
+    return STI_UINT192;
+}
+
 template <>
 inline SerializedTypeID
 STUInt256::getSType() const