Find a Tender API client updates

- Convert OCDS releases to types.Opportunity (internal/types); FetchOnce
  and FetchAll now return opportunities, built from each ocid's latest
  release
- Include each item's main classification as well as its additional ones
- Return ErrUnexpectedStatus for non-200 responses and
  ErrRateLimitExceeded for a repeated 429; close discarded bodies
- Stop fetchAll on a repeated next link and close each page's body once
  read rather than deferring in the loop
- Default a zero Since to 24 hours ago
- Merge date repair and releaseIDs into api.go
- Filter --planning/--opportunities/--awards on each procedure's current
  stage, using OCDS release tags; --opportunities previously matched a
  nonexistent "opportunity" tag and returned nothing
- Reject conflicting filters before fetching (cobra flag group)

internal/findATender/findATender.go

@@ -5,7 +5,7 @@ import (
 	"time"
 
 	"git.avsdev.uk/Go/job-search/internal/config"
-	"git.avsdev.uk/Go/job-search/internal/findATender/ocds"
+	"git.avsdev.uk/Go/job-search/internal/types"
 	resty "resty.dev/v3"
 )
 
@@ -29,7 +29,6 @@ func New(conf *config.JobSearchConfig, apiRoot string) FindATender {
 
 func (ft *FindATender) ReloadConfig(conf *config.JobSearchConfig) {
 	ft.config = conf
-	// TODO: any reloading required for configuration change handling
 }
 
 func (ft *FindATender) With(ctx context.Context) *FindATender {
@@ -49,27 +48,27 @@ func (ft *FindATender) Shutdown() {
 func (ft *FindATender) FetchOnce(
 	since time.Time,
 	allowRateLimit bool,
-) ([]ocds.Release, error) {
-	reqs, err := ft.fetchOnce(RequestOptions{
+) ([]*types.Opportunity, error) {
+	releases, err := ft.fetchOnce(RequestOptions{
 		Since:          since,
 		AllowRateLimit: allowRateLimit,
 	})
 	if err != nil {
 		return nil, err
 	}
-	return reqs, nil
+	return Convert(releases), nil
 }
 
 func (ft *FindATender) FetchAll(
 	since time.Time,
 	allowRateLimit bool,
-) ([]ocds.Release, error) {
-	reqs, err := ft.fetchAll(RequestOptions{
+) ([]*types.Opportunity, error) {
+	releases, err := ft.fetchAll(RequestOptions{
 		Since:          since,
 		AllowRateLimit: allowRateLimit,
 	})
 	if err != nil {
 		return nil, err
 	}
-	return reqs, nil
+	return Convert(releases), nil
 }