Add checksum query expr

modules/query/shared/src/main/scala/docspell/query/ItemQuery.scala

@@ -109,7 +109,8 @@ object ItemQuery {
     final case class CustomFieldIdMatch(id: String, op: Operator, value: String)
         extends Expr
 
-    final case class Fulltext(query: String) extends Expr
+    final case class Fulltext(query: String)         extends Expr
+    final case class ChecksumMatch(checksum: String) extends Expr
 
     // things that can be expressed with terms above
     sealed trait MacroExpr extends Expr {

modules/query/shared/src/main/scala/docspell/query/internal/ExprUtil.scala

@@ -65,6 +65,8 @@ object ExprUtil {
         expr
       case CustomFieldIdMatch(_, _, _) =>
         expr
+      case ChecksumMatch(_) =>
+        expr
     }
 
   private def spliceAnd(nodes: Nel[Expr]): Nel[Expr] =

modules/query/shared/src/main/scala/docspell/query/internal/SimpleExprParser.scala

@@ -76,6 +76,9 @@ object SimpleExprParser {
   val dirExpr: P[Expr.DirectionExpr] =
     (P.string("incoming:") *> BasicParser.bool).map(Expr.DirectionExpr.apply)
 
+  val checksumExpr: P[Expr.ChecksumMatch] =
+    (P.string("checksum:") *> BasicParser.singleString).map(Expr.ChecksumMatch.apply)
+
   val simpleExpr: P[Expr] =
     P.oneOf(
       List(
@@ -89,7 +92,8 @@ object SimpleExprParser {
         customFieldIdExpr,
         customFieldExpr,
         inboxExpr,
-        dirExpr
+        dirExpr,
+        checksumExpr
       )
     )
 }