feat(admin): manually retry an event

[webhookx-x]

Summary

Add a new API to manually retry an event.

POST /workspaces/{ws_id}/events/{id}/retry?endpoint_id={endpoint_id}

issue: #15

[codecov]

Codecov Report

Attention: Patch coverage is 81.48148% with 15 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
dispatcher/dispatcher.go	83.72%	4 Missing and 3 partials ⚠️
admin/api/events.go	62.50%	4 Missing and 2 partials ⚠️
admin/api/api.go	71.42%	1 Missing and 1 partial ⚠️

Flag	Coverage Δ
integration	62.88% <81.48%> (+1.89%)	⬆️
unit	12.48% <0.00%> (-0.42%)	⬇️

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

Files with missing lines	Coverage Δ
app/app.go	85.07% <ø> (ø)
db/dao/attempt_dao.go	85.71% <100.00%> (+0.52%)	⬆️
db/dao/dao.go	88.94% <100.00%> (+0.36%)	⬆️
db/entities/attempt.go	100.00% <ø> (ø)
proxy/gateway.go	61.17% <100.00%> (-0.46%)	⬇️
worker/worker.go	65.00% <100.00%> (+1.94%)	⬆️
admin/api/api.go	91.42% <71.42%> (+0.25%)	⬆️
admin/api/events.go	56.81% <62.50%> (+56.81%)	⬆️
dispatcher/dispatcher.go	77.31% <83.72%> (+2.31%)	⬆️

... and 2 files with indirect coverage changes