Drop redundant CSS properties from java.desktop HTML files

There are a number of <table> elements with "text-align: left" which does not affect visual presentation. Some of <th> elements contain inline style of "text-align: center" which is the default value. These styles can be dropped without changing the way tables look.

Some elements have "vertical-align: top" style which can also be dropped.

The src/java.desktop/share/classes/javax/swing/plaf/synth/doc-files/componentProperties.html file has many tables and most of these issues are in this file.