Introduce a sql literal and constants in query builder

The h2 jdbc driver could not translate the union query in QCollective
when the `kind` was set via a constant value. Using literals works
here. Renamed the corresponding elements in the query builder.

modules/store/src/main/scala/docspell/store/qb/DSL.scala

@@ -101,8 +101,11 @@ trait DSL extends DoobieMeta {
   def concat(expr: SelectExpr, exprs: SelectExpr*): DBFunction =
     DBFunction.Concat(Nel.of(expr, exprs: _*))
 
-  def lit[A](value: A)(implicit P: Put[A]): SelectExpr.SelectLit[A] =
-    SelectExpr.SelectLit(value, None)
+  def const[A](value: A)(implicit P: Put[A]): SelectExpr.SelectConstant[A] =
+    SelectExpr.SelectConstant(value, None)
+
+  def lit(value: String): SelectExpr.SelectLiteral =
+    SelectExpr.SelectLiteral(value, None)
 
   def plus(left: SelectExpr, right: SelectExpr): DBFunction =
     DBFunction.Calc(DBFunction.Operator.Plus, left, right)
@@ -291,7 +294,7 @@ trait DSL extends DoobieMeta {
       DBFunction.Calc(
         DBFunction.Operator.Minus,
         SelectExpr.SelectFun(dbf, None),
-        SelectExpr.SelectLit(value, None)
+        SelectExpr.SelectConstant(value, None)
       )
   }
 }

modules/store/src/main/scala/docspell/store/qb/SelectExpr.scala

@@ -18,9 +18,14 @@ object SelectExpr {
       copy(alias = Some(a))
   }
 
-  case class SelectLit[A](value: A, alias: Option[String])(implicit val P: Put[A])
+  case class SelectConstant[A](value: A, alias: Option[String])(implicit val P: Put[A])
       extends SelectExpr {
-    def as(a: String): SelectLit[A] =
+    def as(a: String): SelectConstant[A] =
+      copy(alias = Some(a))
+  }
+
+  case class SelectLiteral(value: String, alias: Option[String]) extends SelectExpr {
+    def as(a: String): SelectLiteral =
       copy(alias = Some(a))
   }
 

modules/store/src/main/scala/docspell/store/qb/impl/SelectExprBuilder.scala

@@ -12,9 +12,12 @@ object SelectExprBuilder extends CommonBuilder {
       case SelectExpr.SelectColumn(col, alias) =>
         column(col) ++ appendAs(alias)
 
-      case s @ SelectExpr.SelectLit(value, aliasOpt) =>
+      case s @ SelectExpr.SelectConstant(value, aliasOpt) =>
         ConditionBuilder.buildValue(value)(s.P) ++ appendAs(aliasOpt)
 
+      case SelectExpr.SelectLiteral(value, alias) =>
+        Fragment.const(value) ++ appendAs(alias)
+
       case SelectExpr.SelectFun(fun, alias) =>
         DBFunctionBuilder.build(fun) ++ appendAs(alias)
 

modules/store/src/main/scala/docspell/store/queries/QCollective.scala

@@ -28,17 +28,17 @@ object QCollective {
     val created = Column[Timestamp]("created", TableDef(""))
     union(
       Select(
-        select(ro.name.s, lit(1).as("kind"), ro.created.as(created)),
+        select(ro.name.s, lit("1").as("kind"), ro.created.as(created)),
         from(ro),
         ro.cid === collective
       ),
       Select(
-        select(rp.name.s, lit(2).as("kind"), rp.created.as(created)),
+        select(rp.name.s, lit("2").as("kind"), rp.created.as(created)),
         from(rp),
         rp.cid === collective
       ),
       Select(
-        select(re.name.s, lit(3).as("kind"), re.created.as(created)),
+        select(re.name.s, lit("3").as("kind"), re.created.as(created)),
         from(re),
         re.cid === collective
       )

modules/store/src/main/scala/docspell/store/queries/QItem.scala

@@ -138,7 +138,7 @@ object QItem {
         i.source.s,
         i.incoming.s,
         i.created.s,
-        coalesce(Attachs.num.s, lit(0)).s,
+        coalesce(Attachs.num.s, const(0)).s,
         org.oid.s,
         org.name.s,
         pers0.pid.s,
@@ -302,10 +302,10 @@ object QItem {
 
     val basicFields = Nel.of(
       count(i.id).as("fc"),
-      lit(0).as("favg"),
-      lit(0).as("fsum"),
-      lit(0).as("fmax"),
-      lit(0).as("fmin")
+      const(0).as("favg"),
+      const(0).as("fsum"),
+      const(0).as("fmax"),
+      const(0).as("fmin")
     )
     val valueNum = cast(cv.value.s, "decimal").s
     val numericFields = Nel.of(

modules/store/src/main/scala/docspell/store/queries/QJob.scala

@@ -118,8 +118,8 @@ object QJob {
 
   private def stuckTriggerValue(t: RJob.Table, initialPause: Duration, now: Timestamp) =
     plus(
-      coalesce(t.startedmillis.s, lit(now.toMillis)).s,
-      mult(power(2, t.retries.s).s, lit(initialPause.millis)).s
+      coalesce(t.startedmillis.s, const(now.toMillis)).s,
+      mult(power(2, t.retries.s).s, const(initialPause.millis)).s
     )
 
   def selectNextJob(