Archive verification info + Embed improvements + Embed Receipts UI (#125)

info panel verification/integrity additions, (fixes on #113)
- info panel: display number of hashes verified valid (and invalid), observer domain (if any), and certificate fingerprint, creation software, and package digest
- info: ensure replayTS is updated, not just replayUrl, to ensure correct stats

404 page: improved formatting on 404 page (via wabac.js)

embeds:
- new embed 'replay-with-info mode, displays replay-only with dropdown showing archival 'receipt, which includes condensed info and verification (hashes valid/invalid, observer domain, cert fingerprint)
- support 'newWindowBase' attribute for specifying base replay URL for opening new window. default: use current url if deepLink enabled, otherwise use https://replayweb.page/
use transparent for embeds
- embed dropdown/receipt styling from @Shrinks99 
- automatically setting noCache and noWebWorker for older browsers (eg. safari < 16)
- add 'hideOffscreen' attribute to enable unloading embed when offscreen

dependencies: update to wabac.js 2.13.0-beta.0

bump version to 1.7.0-beta.0

Embed receipt styling co-authored-by: @Shrinks99

assets/main.scss

@@ -113,7 +113,7 @@ a:focus {
 
 // Add html and body styles to :host for webcomponents
 :host {
-  background-color: $body-background-color;
+  //background-color: $body-background-color;
   font-size: $body-size;
   -moz-osx-font-smoothing: grayscale;
   -webkit-font-smoothing: antialiased;