As a user, I should be able to export Test Executions List report in Excel format

Description
Add an option to export the Test Executions List report in Excel (.xlsx) format.

User friction
Users cannot easily analyze or share Test Execution data and must manually configure delimiters to display columns correctly in Excel.

Steps to reproduce (current behavior) / Actual Result:

1. Go to Reports → Test Executions List.
2. Configure the desired filters and generate the report.
3. Attempt to export the report data.

Actual Result:
There is no option to export the report in Excel (.xlsx) format.

IMPACT
This limitation restricts reporting, data analysis, and integration with existing workflows.

What would improve if solved:

• Faster report generation

• Easier data manipulation

• Improved visibility of test execution metrics

Impact on stakeholders:
QA Engineers and QA Managers can create and share reports more efficiently with other stakeholders.

Current workaround:
Export the report as CSV and manually set the delimiter to ";" in order to separate the data into columns.

Concrete example:
A QA Manager needs a weekly Excel report of Test Executions but must export it as CSV and manually configure the delimiter as a semicolon.

Workaround risk:
Using a semicolon as a delimiter can cause data loss or formatting issues when field values contain commas, leading to inaccurate reports.
This happens because excel opens, by default as CSV UTF-8 (Comma delimited), this causes information to be split at the comma and if we then set the delimiter to the first column, it will overwrite the other columns.