[JIRAALIGN-1244] Team weeks and other numbers are not in number format on the Excel Program Epic export

Issue Summary

Cells that are supposed to be numbers are stored as text on the exported program epics.

Steps to Reproduce

1. Navigate to Epic Grid and make sure there are results.
2. Click "More Actions" > Export 

Expected Results

JA fields for epics that are numbers should be also be stored as numbers in the exported excel file.

Actual Results

JA fields for epics that are numbers are stored as text in the exported excel file.

Example:

• Team Weeks

  Workaround

User have to manually change the cells from text to numbers in excel so that they can use excel formulas for calculations.