Use stable files API URLs for vendor logo fields

CommonThirdParty.logoUrl and TrustCenterReference.logoUrl were
returning expiring S3 presigned URLs, which break if cached or
shared past their TTL.

Replace with stable /api/files/v1/{id} application URLs.
file.Service now generates these via baseurl; a new filesign
package owns presigning for the files/v1 HTTP handler that
does the internal redirect.

Signed-off-by: Ludovic Vielle <ludovic@probo.com>

pkg/trust/service.go

@@ -26,6 +26,7 @@ import (
 	"go.probo.inc/probo/packages/emails"
 	"go.probo.inc/probo/pkg/coredata"
 	"go.probo.inc/probo/pkg/esign"
+	"go.probo.inc/probo/pkg/file"
 	"go.probo.inc/probo/pkg/filemanager"
 	"go.probo.inc/probo/pkg/gid"
 	"go.probo.inc/probo/pkg/html2pdf"
@@ -46,6 +47,7 @@ type (
 		esign                  *esign.Service
 		html2pdfConverter      *html2pdf.Converter
 		fileManager            *filemanager.Service
+		file                   *file.Service
 		logger                 *log.Logger
 		slack                  *slack.Service
 		TrustCenters           *TrustCenterService
@@ -75,6 +77,7 @@ func NewService(
 	fileManagerService *filemanager.Service,
 	logger *log.Logger,
 	slack *slack.Service,
+	fileService *file.Service,
 ) *Service {
 	svc := &Service{
 		pg:                 pgClient,
@@ -86,6 +89,7 @@ func NewService(
 		esign:              esignSvc,
 		html2pdfConverter:  html2pdfConverter,
 		fileManager:        fileManagerService,
+		file:               fileService,
 		logger:             logger,
 		slack:              slack,
 	}