Require and Entity and TaxImplication tag for outgoing payments over $10.

This now enforces what was said in the documentation in the previous commit:

   The `TaxImplication:` tag is used for all `Asset:` accounts when the
   transaction includes a payment of $10.00 or more leaving the
   account. .... An [`Entity:` tag](entity-tag) should always go along with a
   TaxImplication tag.

accounts/config/config-accounts.ledger

@@ -18,7 +18,10 @@
 
 ; Shared Asset Accounts
 
+define assetChecker(amt) = (amt > -10.00 or (tag("TaxImplication") !~ /^\s*$/ and tag("Entity") !~ /^\s*$/))
+
 account Asset:Checking
+   assert assetChecker(amount)
    note Checking account for entire organization
    assert commodity == "$"