fix: revert ExpressionProperties to Properties in BaseDataSource

ExpressionProperties is used for a specific property to avoid unexpected behaviors for already existing properties (e.g. passwords with ${...})

pgjdbc/src/main/java/org/postgresql/ds/common/BaseDataSource.java

@@ -50,7 +50,7 @@
  private int portNumber = 0;

  // Map for all other properties
  private Properties properties = new ExpressionProperties();
  private Properties properties = new Properties();

  /**
   * Gets a connection to the PostgreSQL database. The database is identified by the DataSource