Support for NetworkID

[nkramer44]

Adds support for the NetworkID transaction field. This field is Optional in Transaction, as it is only required on networks with ID > 1024.

Fixes #427

[codecov[bot]]

Codecov Report

Merging #461 (5b6e7c9) into main (100a5b3) will increase coverage by 0.02%. The diff coverage is 100.00%.

@@             Coverage Diff              @@
##               main     #461      +/-   ##
============================================
+ Coverage     90.44%   90.46%   +0.02%     
- Complexity     1464     1468       +4     
============================================
  Files           285      287       +2     
  Lines          4164     4174      +10     
  Branches        339      339              
============================================
+ Hits           3766     3776      +10     
  Misses          277      277              
  Partials        121      121              

Files Changed	Coverage Δ
...rpl/xrpl4j/model/client/serverinfo/ServerInfo.java	88.88% <ø> (ø)
...rg/xrpl/xrpl4j/model/transactions/Transaction.java	100.00% <ø> (ø)
...j/model/jackson/modules/NetworkIdDeserializer.java	100.00% <100.00%> (ø)
...l4j/model/jackson/modules/NetworkIdSerializer.java	100.00% <100.00%> (ø)
...a/org/xrpl/xrpl4j/model/transactions/Wrappers.java	89.55% <100.00%> (+0.48%)	:arrow_up: