Configure IntelliJ to respect @LateInit annotations (#1606)

IntelliJ can understand that some annotations on fields mean that they
are implicitly initialized, which means we don't get the "field XXX is
not initialized" warning for `@LateInit` fields.

This setting, unfortunately, is recorded into `.idea/misc.xml`, which
contains a bunch of arbitrary stuff that we don't want to check into
source control

This adds some logic to touch up that file to mark `@LateInit` as
implicitly initialized fields, so we don't get any editor warnings.

Also, suppress some warnings.

pkl-core/src/main/java/org/pkl/core/TypeAlias.java

@@ -47,6 +47,7 @@ public final class TypeAlias extends Member implements Value {
   }
 
   public void initAliasedType(PType type) {
+    //noinspection ConstantValue
     assert aliasedType == null;
     aliasedType = type;
   }
@@ -80,6 +81,7 @@ public final class TypeAlias extends Member implements Value {
 
   /** Returns the type that this type alias stands for. */
   public PType getAliasedType() {
+    //noinspection ConstantValue
     assert aliasedType != null;
     return aliasedType;
   }