lint: Fix errors showing up w/ golanci-lint

[Eric-Warehime]

Summary

Corrects most of the errors showing up when I merge the 2.15.0 release changes (including golangci-lint) into develop.

• misspellings
• unhandled errors -- I've chosen to acknowledge those instead of handle them explicitly
• import order

[codecov]

Codecov Report

Merging #1358 (9df33cb) into develop (d672efe) will not change coverage.
The diff coverage is 50.00%.

@@           Coverage Diff            @@
##           develop    #1358   +/-   ##
========================================
  Coverage    60.71%   60.71%           
========================================
  Files           76       76           
  Lines        10909    10909           
========================================
  Hits          6623     6623           
  Misses        3699     3699           
  Partials       587      587           

Impacted Files	Coverage Δ
conduit/errors.go	0.00% <0.00%> (ø)
conduit/plugins/exporters/postgresql/util/prune.go	75.00% <ø> (ø)
conduit/plugins/importers/algod/algod_importer.go	78.02% <ø> (ø)
conduit/plugins/importers/filereader/filereader.go	89.06% <ø> (ø)
...ugins/processors/blockprocessor/block_processor.go	66.39% <ø> (ø)
...it/plugins/processors/blockprocessor/initialize.go	63.88% <ø> (ø)
...lugins/processors/filterprocessor/fields/filter.go	80.00% <ø> (ø)
...gins/processors/filterprocessor/fields/searcher.go	82.69% <0.00%> (ø)
...ins/processors/filterprocessor/filter_processor.go	82.66% <ø> (ø)
util/util.go	76.92% <ø> (ø)
... and 2 more

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