NextReports: Excel Sheet Name

When a report is generated as Excel, sheets are named as "Page1", "Page 2" and so on. This is hard coded till version 7.3.

But starting with 7.3 version a new 'excel sheet name' property is used to address this issue.

If this property is left empty, sheets will have names like 1, 2, 3, ....

If user wants to use it, he has three options:

1. Use a static list of strings: This is useful if you know from start how many sheets you have. For example A;B;C;D will name the first four sheets in this order as A, B, C, D.  If there are more sheets than elements in the list, next sheets will have their page number as name.
2. Use a template  marker for page number ${NO}. For example Page ${NO} will name the sheets as Page 1, Page 2, Page 3, ...
3. Use a template marker for group name ${G1}. This is useful if you have a group and you set "new page" after the group finishes, so you have group specific data on different sheets. In this case the sheets will be named with the group name. If there are more sheets than groups, next sheets will have their page number as name.