conduit: update plugin interface types

[shiqizng]

resolves #1438

[shiqizng]

I will rebase when #1468 is merged.

[codecov]

Codecov Report

Merging #1473 (1b1819f) into develop (caddb25) will decrease coverage by 0.22%.
The diff coverage is 57.02%.

@@             Coverage Diff             @@
##           develop    #1473      +/-   ##
===========================================
- Coverage    65.61%   65.40%   -0.22%     
===========================================
  Files           82       82              
  Lines        11384    11443      +59     
===========================================
+ Hits          7470     7484      +14     
- Misses        3353     3389      +36     
- Partials       561      570       +9     

Impacted Files	Coverage Δ
...plugins/processors/filterprocessor/gen/generate.go	36.92% <0.00%> (ø)
...filterprocessor/fields/generated_signed_txn_map.go	17.08% <18.75%> (ø)
...ugins/processors/blockprocessor/block_processor.go	70.83% <40.00%> (-3.07%)	⬇️
conduit/init_provider.go	55.55% <50.00%> (ø)
...lugins/exporters/postgresql/postgresql_exporter.go	78.75% <60.00%> (+0.72%)	⬆️
helpers/helpers.go	34.69% <61.70%> (+1.36%)	⬆️
data/block_export_data.go	80.00% <78.26%> (-2.70%)	⬇️
conduit/pipeline/pipeline.go	64.32% <100.00%> (ø)
conduit/plugins/importers/algod/algod_importer.go	77.96% <100.00%> (ø)
...lugins/processors/filterprocessor/fields/filter.go	80.00% <100.00%> (ø)
... and 5 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[Eric-Warehime]

Can we get rid of this now? What else needs the encoded block cert converted after this PR?

[shiqizng]

block_processor still uses this. we can remove it when removing the block_processor which is one of the last steps.