Use well known test keys only in unit test code

[hewison-chris]

The agora.utils.Test.WK keys we use for convenience in test code are not required to be loaded when we use TxBuilder in Faucet to create transactions using other keys.

[codecov[bot]]

Codecov Report

Merging #3263 (b9f3069) into v0.x.x (6bd2cb2) will decrease coverage by 54.49%. The diff coverage is n/a.

@@             Coverage Diff             @@
##           v0.x.x    #3263       +/-   ##
===========================================
- Coverage   88.67%   34.17%   -54.50%     
===========================================
  Files         165       35      -130     
  Lines       17030     1902    -15128     
===========================================
- Hits        15101      650    -14451     
+ Misses       1929     1252      -677     

Flag	Coverage Δ
integration	34.17% <ø> (+3.61%)	:arrow_up:
unittests	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
source/agora/utils/TxBuilder.d	0.00% <ø> (-98.58%)	:arrow_down:
source/agora/script/Stack.d	0.00% <0.00%> (-100.00%)	:arrow_down:
source/agora/script/Script.d	0.00% <0.00%> (-100.00%)	:arrow_down:
source/agora/utils/Backoff.d	0.00% <0.00%> (-100.00%)	:arrow_down:
source/agora/script/Opcodes.d	0.00% <0.00%> (-100.00%)	:arrow_down:
source/agora/stats/Collector.d	0.00% <0.00%> (-100.00%)	:arrow_down:
source/agora/stats/StatFormatter.d	0.00% <0.00%> (-100.00%)	:arrow_down:
source/scpd/quorum/QuorumTracker.d	0.00% <0.00%> (-100.00%)	:arrow_down:
source/agora/script/ScopeCondition.d	0.00% <0.00%> (-100.00%)	:arrow_down:
source/agora/utils/Utility.d	0.00% <0.00%> (-96.43%)	:arrow_down:
... and 149 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 6bd2cb2...b9f3069. Read the comment docs.

[hewison-chris]

Found solution in other branch.