Attachments: Add extension support, allow all types for releases (#12465)

* Attachments: Add extension support, allow all types for releases

- Add support for file extensions, matching the `accept` attribute of `<input type="file">`
- Add support for type wildcard mime types, e.g. `image/*`
- Create repository.release.ALLOWED_TYPES setting (default unrestricted)
- Change default for attachment.ALLOWED_TYPES to a list of extensions
- Split out POST /attachments into two endpoints for issue/pr and
  releases to prevent circumvention of allowed types check

Fixes: https://github.com/go-gitea/gitea/pull/10172
Fixes: https://github.com/go-gitea/gitea/issues/7266
Fixes: https://github.com/go-gitea/gitea/pull/12460
Ref: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/file#Unique_file_type_specifiers

* rename function

* extract GET routes out of RepoMustNotBeArchived

Co-authored-by: Lauris BH <lauris@nix.lv>

routers/repo/release.go

@@ -16,6 +16,7 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/markup/markdown"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/upload"
 	releaseservice "code.gitea.io/gitea/services/release"
 )
 
@@ -192,7 +193,8 @@ func NewRelease(ctx *context.Context) {
 	ctx.Data["Title"] = ctx.Tr("repo.release.new_release")
 	ctx.Data["PageIsReleaseList"] = true
 	ctx.Data["tag_target"] = ctx.Repo.Repository.DefaultBranch
-	renderAttachmentSettings(ctx)
+	ctx.Data["IsAttachmentEnabled"] = setting.Attachment.Enabled
+	upload.AddUploadContext(ctx, "release")
 	ctx.HTML(200, tplReleaseNew)
 }
 
@@ -278,7 +280,8 @@ func EditRelease(ctx *context.Context) {
 	ctx.Data["Title"] = ctx.Tr("repo.release.edit_release")
 	ctx.Data["PageIsReleaseList"] = true
 	ctx.Data["PageIsEditRelease"] = true
-	renderAttachmentSettings(ctx)
+	ctx.Data["IsAttachmentEnabled"] = setting.Attachment.Enabled
+	upload.AddUploadContext(ctx, "release")
 
 	tagName := ctx.Params("*")
 	rel, err := models.GetRelease(ctx.Repo.Repository.ID, tagName)