Adapt the testsuite to use SSE

[Geod24]

Also includes two improvements to SSE themselves.

Fixes #909

[codecov-io]

Codecov Report

Merging #919 into master will increase coverage by 0.65%. The diff coverage is 56.25%.

@@            Coverage Diff             @@
##           master     #919      +/-   ##
==========================================
+ Coverage   60.12%   60.78%   +0.65%     
==========================================
  Files         159      159              
  Lines       11203    11217      +14     
==========================================
+ Hits         6736     6818      +82     
+ Misses       3674     3597      -77     
- Partials      793      802       +9

Flag	Coverage Δ
#integration_tests_long_term	44.06% <0%> (-0.02%)	:arrow_down:
#integration_tests_node	41.19% <56.25%> (?)
#integration_tests_retry	37.16% <0%> (-0.06%)	:arrow_down:
#unittests	47.67% <0%> (-0.02%)	:arrow_down:

Impacted Files	Coverage Δ
lib/client/client.go	3.38% <0%> (-0.08%)	:arrow_down:
lib/node/runner/api/stream.go	63.35% <100%> (+20.73%)	:arrow_up:
lib/node/runner/checker.go	73.58% <0%> (+0.22%)	:arrow_up:
lib/node/runner/finish_ballot.go	45.28% <0%> (+1.41%)	:arrow_up:
lib/node/runner/util.go	75% <0%> (+3.57%)	:arrow_up:
lib/transaction/checker.go	81.81% <0%> (+3.63%)	:arrow_up:
lib/block/transaction_pool.go	56.6% <0%> (+3.77%)	:arrow_up:
lib/network/http2_network_log.go	94.28% <0%> (+5.71%)	:arrow_up:
lib/errors/base.go	90.69% <0%> (+9.3%)	:arrow_up:
lib/node/runner/node_api/api_node_item.go	64.1% <0%> (+10.25%)	:arrow_up:
... and 6 more

---

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[codecov-io]

Codecov Report

Merging #919 into master will decrease coverage by 13.88%. The diff coverage is 56.25%.

@@            Coverage Diff             @@
##           master    #919       +/-   ##
==========================================
- Coverage   60.78%   46.9%   -13.89%     
==========================================
  Files         160     158        -2     
  Lines       11247   11018      -229     
==========================================
- Hits         6837    5168     -1669     
- Misses       3606    5088     +1482     
+ Partials      804     762       -42

Flag	Coverage Δ
#integration_tests_long_term	44% <0%> (+0.12%)	:arrow_up:
#integration_tests_node	41.17% <56.25%> (+0.62%)	:arrow_up:
#integration_tests_retry	37.66% <0%> (-0.14%)	:arrow_down:
#unittests	?

Impacted Files	Coverage Δ
lib/client/client.go	3.38% <0%> (-0.08%)	:arrow_down:
lib/node/runner/api/stream.go	55.72% <100%> (+13.1%)	:arrow_up:
lib/transaction/operation/test.go	0% <0%> (-100%)	:arrow_down:
lib/network/test.go	0% <0%> (-100%)	:arrow_down:
lib/node/runner/test_connection_manager.go	0% <0%> (-94.45%)	:arrow_down:
lib/node/runner/api/resource/resource.go	0% <0%> (-91.67%)	:arrow_down:
lib/node/runner/test.go	0% <0%> (-89.07%)	:arrow_down:
lib/node/runner/api/pagequery.go	0% <0%> (-86.42%)	:arrow_down:
lib/node/runner/api/resource/operation.go	0% <0%> (-83.34%)	:arrow_down:
lib/network/httpcache/mem.go	0% <0%> (-76.48%)	:arrow_down:
... and 71 more

---

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Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update cc3eb02...d0f6128. Read the comment docs.

[Geod24]

Updated according to @Charleslee522 's comments