server: add unread field to tag query.

Optionally fill out unread, as it's expensive.

Cargo.lock

@@ -437,16 +437,6 @@ dependencies = [
  "cfg-if 1.0.0",
 ]
 
-[[package]]
-name = "crossbeam-channel"
-version = "0.5.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a33c2bf77f2df06183c3aa30d1e96c0695a313d4f9c453cc3762a6db39f99200"
-dependencies = [
- "cfg-if 1.0.0",
- "crossbeam-utils",
-]
-
 [[package]]
 name = "crossbeam-deque"
 version = "0.8.3"
@@ -2235,9 +2225,9 @@ dependencies = [
 
 [[package]]
 name = "rayon"
-version = "1.7.0"
+version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d2df5196e37bcc87abebc0053e20787d73847bb33134a69841207dd0a47f03b"
+checksum = "9c27db03db7734835b3f53954b534c91069375ce6ccaa2e065441e07d9b6cdb1"
 dependencies = [
  "either",
  "rayon-core",
@@ -2245,14 +2235,12 @@ dependencies = [
 
 [[package]]
 name = "rayon-core"
-version = "1.11.0"
+version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b8f95bd6966f5c87776639160a66bd8ab9895d9d4ab01ddba9fc60661aebe8d"
+checksum = "5ce3fb6ad83f861aac485e76e1985cd109d9a3713802152be56c3b1f0e0658ed"
 dependencies = [
- "crossbeam-channel",
  "crossbeam-deque",
  "crossbeam-utils",
- "num_cpus",
 ]
 
 [[package]]
@@ -2730,6 +2718,7 @@ dependencies = [
  "glog",
  "log 0.4.20",
  "notmuch",
+ "rayon",
  "rocket 0.5.0",
  "rocket_contrib",
  "rocket_cors",