Fix transaction deserializaation and enhance unit tests

[sappenin]

Once #594 is merged, this PR improves test coverage of all Transaction sub-classes by adding enhanced JSON deserialization coverage for each flavor of each Transaction. For example the Payment transaction can be deserialized via at least three different mechanisms:

1. By pointing the Jackson ObjectMapper to a Transaction class (in which case, TransactionDeserializer will be engaged, delegating to the Immutable JSON implementation);
2. By pointing the Jackson ObjectMapper to a Payment class (in which case, the TransactionDeserialer will be skipped and the Transaction interface will be used, delegating to the to the Immutable JSON implementation);
3. By pointing the Jackson ObjectMapper to the Immutable implementation itself (e.g., an ImmutablePayment).

This PR adds this additional coverage to ensure proper JSON handling by future developers who may change certain aspects of each Transaction's Interface/Immutable or concrete deserializer without realizing that these changes might subtly affect deserialization based on other related classes.

[codecov]

Codecov Report

Attention: Patch coverage is 28.87701% with 133 lines in your changes missing coverage. Please review.

Project coverage is 89.80%. Comparing base (a69b5f1) to head (7f7e86f).

Files with missing lines	Patch %	Lines
.../xrpl/xrpl4j/model/transactions/AccountDelete.java	25.00%	0 Missing and 3 partials ⚠️
...org/xrpl/xrpl4j/model/transactions/AccountSet.java	25.00%	0 Missing and 3 partials ⚠️
...ava/org/xrpl/xrpl4j/model/transactions/AmmBid.java	25.00%	0 Missing and 3 partials ⚠️
.../org/xrpl/xrpl4j/model/transactions/AmmCreate.java	25.00%	0 Missing and 3 partials ⚠️
.../org/xrpl/xrpl4j/model/transactions/AmmDelete.java	25.00%	0 Missing and 3 partials ⚠️
...org/xrpl/xrpl4j/model/transactions/AmmDeposit.java	25.00%	0 Missing and 3 partials ⚠️
...va/org/xrpl/xrpl4j/model/transactions/AmmVote.java	25.00%	0 Missing and 3 partials ⚠️
...rg/xrpl/xrpl4j/model/transactions/AmmWithdraw.java	25.00%	0 Missing and 3 partials ⚠️
...rg/xrpl/xrpl4j/model/transactions/CheckCancel.java	25.00%	0 Missing and 3 partials ⚠️
.../org/xrpl/xrpl4j/model/transactions/CheckCash.java	25.00%	0 Missing and 3 partials ⚠️
... and 35 more

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #593      +/-   ##
============================================
- Coverage     92.01%   89.80%   -2.22%     
- Complexity     1848     1893      +45     
============================================
  Files           383      383              
  Lines          5125     5305     +180     
  Branches        435      524      +89     
============================================
+ Hits           4716     4764      +48     
  Misses          273      273              
- Partials        136      268     +132     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.