Automated reconcillation execution

**Epic Description:**
As a SaaS company specializing in bank reconciliation, we aim to provide our users with a seamless and automated reconciliation process. This epic focuses on developing a feature that can execute reconciliation using two Excel files - one from the bank and one labeled as '502'. The key areas of development include:

1. **Excel File Upload:** Develop a secure and efficient feature for users to upload their Excel files. This includes validating the file format and size and handling any upload errors.

2. **Data Extraction:** Implement a feature to extract and validate data from the uploaded Excel files. This includes mapping the data fields correctly between the bank and 502 files.

3. **Reconciliation Process:** Develop an automated reconciliation process that matches records between the two Excel files, identifies discrepancies, and generates reconciliation reports.

4. **Error Handling:** Implement robust error handling to deal with any issues during the reconciliation process. This includes providing clear and informative error messages to the users.

5. **User Interface:** Design a user-friendly interface for uploading Excel files and viewing reconciliation results. This includes progress indicators for the reconciliation process and intuitive displays for viewing and analyzing reconciliation reports.

**Acceptance Criteria:**
- Successful upload and validation of Excel files.
- Accurate extraction and mapping of data from Excel files.
- Efficient and accurate reconciliation process.
- Robust error handling during the reconciliation process.
- User-friendly interface for executing reconciliation and viewing results.