Some Blob registration functionality is only used for internal URLs. This change makes clear that registering a Blob URL is restricted to internal URLs and there isn't an associated top origin. There are two remaining registration functions that accept an optional SecurityOriginData and those functions are used for registering both public and internal blob URLs.
<rdar://problem/111107487>
Pull request: https://github.com/WebKit/WebKit/pull/15149
Committed 265789@main (20a4f6d1b5da): <https://commits.webkit.org/265789@main> Reviewed commits have been landed. Closing PR #15149 and removing active labels.