[performance] improved request batching (removes need for queueing) (#1687)

* revamp http client to not limit requests, instead use sender worker

Signed-off-by: kim <grufwub@gmail.com>

* remove separate sender worker pool, spawn 2*GOMAXPROCS batch senders each time, no need for transport cache sweeping

Signed-off-by: kim <grufwub@gmail.com>

* improve batch senders to keep popping recipients until remote URL found

Signed-off-by: kim <grufwub@gmail.com>

* fix recipient looping issue

Signed-off-by: kim <grufwub@gmail.com>

* fix missing mutex unlock

Signed-off-by: kim <grufwub@gmail.com>

* move request id ctx key to gtscontext, finish filling out more code comments, add basic support for not logging client IP

Signed-off-by: kim <grufwub@gmail.com>

* slight code reformatting

Signed-off-by: kim <grufwub@gmail.com>

* a whitespace

Signed-off-by: kim <grufwub@gmail.com>

* remove unused code

Signed-off-by: kim <grufwub@gmail.com>

* add missing license headers

Signed-off-by: kim <grufwub@gmail.com>

* fix request backoff calculation

Signed-off-by: kim <grufwub@gmail.com>

---------

Signed-off-by: kim <grufwub@gmail.com>

internal/processing/account/get.go

@@ -25,9 +25,9 @@ import (
 
 	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtscontext"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
-	"github.com/superseriousbusiness/gotosocial/internal/transport"
 )
 
 // Get processes the given request for account information.
@@ -96,7 +96,7 @@ func (p *Processor) getFor(ctx context.Context, requestingAccount *gtsmodel.Acco
 		}
 
 		a, err := p.federator.GetAccountByURI(
-			transport.WithFastfail(ctx), requestingAccount.Username, targetAccountURI, true,
+			gtscontext.SetFastFail(ctx), requestingAccount.Username, targetAccountURI, true,
 		)
 		if err == nil {
 			targetAccount = a