Speed up pagination in buildAccountQuery when Asset or App id are provided

[urtho]

Problem

Next token is ignored in some CTEs causing full table scans during pagination.

Solution

This patch shows x5 speedup in average query exec time. Not an ultimate solution but a quick win.

--- a/idb/postgres/postgres.go
+++ b/idb/postgres/postgres.go
@@ -1797,13 +1797,25 @@ func (db *IndexerDb) buildAccountQuery(opts idb.AccountQueryOptions, countOnly b
                        whereArgs = append(whereArgs, *opts.AssetLT)
                        partNumber++
                }
+               if len(opts.GreaterThanAddress) > 0 {
+                       aq += fmt.Sprintf(" AND addr > $%d", partNumber)
+                       whereArgs = append(whereArgs, opts.GreaterThanAddress)
+                       partNumber++
+               }
                aq = "qasf AS (" + aq + ")"
                withClauses = append(withClauses, aq)
        }
        if opts.HasAppID != 0 {
-               withClauses = append(withClauses, fmt.Sprintf("qapf AS (SELECT addr FROM account_app WHERE app = $%d)", partNumber))
+               aq := fmt.Sprintf("SELECT addr FROM account_app WHERE app = $%d", partNumber)
                whereArgs = append(whereArgs, opts.HasAppID)
                partNumber++
+               if len(opts.GreaterThanAddress) > 0 {
+                       aq += fmt.Sprintf(" AND addr > $%d", partNumber)
+                       whereArgs = append(whereArgs, opts.GreaterThanAddress)
+                       partNumber++
+               }
+               aq = "qapf AS (" + aq + ")"
+               withClauses = append(withClauses, aq)