[bugfix] 2643 bug search for account url doesnt always work when redirected (#2673)

* update activity library so dereferencer returns full response and checks *final* link to allow for redirects

* temporarily add bodged fixed library

* remove unused code

* update getAccountFeatured() to use dereferenceCollectionPage()

* make sure to release map

* perform a 2nd decode to ensure reader is empty after primary decode

* add comment explaining choice of using Decode() instead of Unmarshal()

* update embedded activity library to latest matching https://github.com/superseriousbusiness/activity/pull/21

* add checks to look for changed URI and re-check database if redirected

* update max iteration count to 512, add checks during dereferenceAncestors() for indirect URLs

* remove doubled-up code

* fix use of status instead of current

* use URIs for checking equality for security

* use the latest known URI for boost_of_uri in case original was an indirect

* add dereferenceCollection() function for dereferenceAccountFeatured()

* pull in latest github.com/superseriousbusiness/activity version (and remove the bodge!!)

* fix typo in code comments

* update decodeType() to accept a readcloser and handle body closing

* switch to checking using BoostOfID and add note why not using BoostOfURI

* ensure InReplyTo gets unset when deleting status parent in case currently stubbed

* add tests for Collection and CollectionPage iterators

internal/ap/util.go

@@ -19,10 +19,39 @@ package ap
 
 import (
 	"net/url"
+	"sync"
 
 	"github.com/superseriousbusiness/activity/streams/vocab"
 )
 
+const mapmax = 256
+
+// mapPool is a memory pool
+// of maps for JSON decoding.
+var mapPool sync.Pool
+
+// getMap acquires a map from memory pool.
+func getMap() map[string]any {
+	v := mapPool.Get()
+	if v == nil {
+		// preallocate map of max-size.
+		m := make(map[string]any, mapmax)
+		v = m
+	}
+	return v.(map[string]any) //nolint
+}
+
+// putMap clears and places map back in pool.
+func putMap(m map[string]any) {
+	if len(m) > mapmax {
+		// drop maps beyond
+		// our maximum size.
+		return
+	}
+	clear(m)
+	mapPool.Put(m)
+}
+
 // _TypeOrIRI wraps a vocab.Type to implement TypeOrIRI.
 type _TypeOrIRI struct {
 	vocab.Type