Refactor Covalent Handling

[JamesSmartCell]

• Refactor Covalent Handling
• Add covalent unit test

Closes #2755

[github-actions]

Pull reviewers stats

Stats of the last 30 days for alpha-wallet-android:

	User	Total reviews	Time to review	Total comments
	JamesSmartCell 🥇	9 ▀▀▀▀▀	20h 27m ▀▀▀	13 ▀▀▀▀▀▀▀
	seabornlee 🥈	7 ▀▀▀▀	2h 19m	7 ▀▀▀▀
	justindg 🥉	1 ▀	1d 19h 5m ▀▀▀▀▀▀▀	0

[codecov]

Codecov Report

Base: 7.41% // Head: 7.64% // Increases project coverage by +0.23% 🎉

Coverage data is based on head (8602a2c) compared to base (fe5afcd).
Patch coverage: 66.66% of modified lines in pull request are covered.

❗ Current head 8602a2c differs from pull request most recent head 3985f66. Consider uploading reports for the commit 3985f66 to get more accurate results

Additional details and impacted files

@@             Coverage Diff             @@
##             master   #2801      +/-   ##
===========================================
+ Coverage      7.41%   7.64%   +0.23%     
- Complexity      779     800      +21     
===========================================
  Files           575     575              
  Lines         40601   40597       -4     
  Branches       4133    4135       +2     
===========================================
+ Hits           3011    3105      +94     
+ Misses        37334   37223     -111     
- Partials        256     269      +13     

Impacted Files	Coverage Δ
...awallet/app/service/TransactionsNetworkClient.java	2.89% <ø> (ø)
...om/alphawallet/app/entity/CovalentTransaction.java	63.29% <66.66%> (+63.29%)	⬆️
.../src/main/java/com/alphawallet/app/util/Utils.java	9.32% <0.00%> (+0.25%)	⬆️
...n/java/com/alphawallet/app/entity/Transaction.java	6.89% <0.00%> (+6.89%)	⬆️
...ava/com/alphawallet/app/entity/EtherscanEvent.java	8.33% <0.00%> (+8.33%)	⬆️
...m/alphawallet/app/entity/EtherscanTransaction.java	68.96% <0.00%> (+68.96%)	⬆️

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[seabornlee]

LGTM, did minor refactoring.