feat_: add fallback pairing support (#20921)

Creating this PR for regression testing the comparability of feature sync
between different versions(mainly current PR build vs v2.29) after adding
backend fallback pairing support. Because frontend haven't added the invocations
relate to fallback pairing API yet, so fallback pairing won't support with
current build.

relate status-go PR status-im/status-go#5614

Testing notes expected: sync should work as before between different versions
like following: v2.29 <-> PR build PR build <-> recent desktop build

NOTE: It breaks with v1 of pairing, but that's ancient (last year I believe), so
safe to break.

status-go-version.json

@@ -3,7 +3,7 @@
     "_comment": "Instead use: scripts/update-status-go.sh <rev>",
     "owner": "status-im",
     "repo": "status-go",
-    "version": "v0.182.39",
-    "commit-sha1": "9755b3de7ae64929066d2b8a26222d8d41ceda87",
-    "src-sha256": "02b2fshb7phhsr7mghg4s6qr1n1c8xawaz4pw04q8hpv5vfnjcxz"
+    "version": "v0.182.40",
+    "commit-sha1": "9ef122b89551f2210946e0d3094ee0225aa39b75",
+    "src-sha256": "0pd2kjc3g7cfvg7j0w7lsaczk5za2c2259sbidjjhr0v54cfys0l"
 }