Add delete election functionality, Update ElectionOrganizer and ElectionStorage.

Description

Here I have added delete election functionality to my last merge request(!66)

Fixes # (issue)

• Improve/Update the solidity code of ElectionOrganizer.sol and ElectionStorage.sol.
• Improve/Update Delete Election Modal to have this functionality.
• Improve/Update Election.js to have this functionality.
• Add navigation to the dashboard after the election is deleted.
• Add a relevant alert message.

Delete_Election
Whenever I go to the right and wait, it's basically I am doing transaction using metamask.

Type of change

Please mark the options that are relevant.

• Improved the business logic of code
• Added new feature/functionality
• Added relevant alert

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings