Adopt NEFilterSource SPI to set delegation.
<rdar://problem/109900099>
Pull request: https://github.com/WebKit/WebKit/pull/15107
Committed 265376@main (238e3a40fcca): <https://commits.webkit.org/265376@main> Reviewed commits have been landed. Closing PR #15107 and removing active labels.
Committed 265383@main (65eff3fa4fa3): <https://commits.webkit.org/265383@main> Reviewed commits have been landed. Closing PR #15169 and removing active labels.
Re-opening for pull request https://github.com/WebKit/WebKit/pull/15199
Committed 265463@main (4b893edcda1f): <https://commits.webkit.org/265463@main> Reviewed commits have been landed. Closing PR #15199 and removing active labels.