Issue #3038523 by cboyden, Gauravvvv, mgifford, Luke.Leber, Chi: Add aria-current attribute to navigation items

Issue #1975064 by smustgrave, tanc, ravi.shankar, seanpclark, pixlkat, wengerk, meena.bisht, cboyden, rjg, klaasvw, nikitagupta, larowlan, MaskOta, mlncn, dsnopek, fenstrat, fago, vacho, yobottehg, Grimreaper, rpayanm, B-Prod, SKAUGHT, rkoller, yoroy, stefan.r, psf_, AaronMcHale, rootwork, ifrik, TravisCarden, stella, kae76, josephdpurcell@gmail.com, eelkeblok, andypost, benjifisher: Add more granular block permissions

Issue #3027653 by clayfreeman, tim.plunkett, Pavel Ruban, raman.b, ankithashetty, cboyden, larowlan, mpotter, phenaproxima: Allow block and layout plugins to determine if they are being previewed

Issue #3087405 by andrewmacpherson, bnjmnm, phenaproxima, rainbreaw, annagaz, cboyden: For screenreader users using the media and media library UI, the words "remove" and "removed" sound too similar

Issue #3082690 by phenaproxima, bnjmnm, oknate, JeroenT, effulgentsia, xjm, lauriii, webchick, seanB, andrewmacpherson, Wim Leers, DyanneNova, Gábor Hojtsy, cboyden, peterx, rainbreaw, jan.stoeckler, shaal, annagaz, FeyP, chr.fritsch, marcoscano, samuel.mortenson, Berdir, webflo: Mark Media Library as a stable core module

Issue #2959493 by bnjmnm, phenaproxima, tim.plunkett, tedbow, Adrian83, lauriii, xjm, andrewmacpherson, johndevman, KarenS, alwaysworking, jrockowitz, ckrina, cboyden, webchick, seanB, benjifisher, larowlan: Allow Layout Builder live previews to be toggled to allow easier drag-and-drop

(cherry picked from commit d028385c)

Issue #3041143 by tim.plunkett, cboyden, xjm, phenaproxima, rainbreaw: Add ARIA group roles to Layout Builder UI

Issue #2531700 by dmsmidt, alexrayu, cboyden, finne, tameeshb, kattekrab, andrewmacpherson, hass, droplet, drpal, dsnopek, nod_: Fragment links to children elements in closed grouping elements don't work