Revert "Add total XP table" feature

[RichDom2185]

Description

This PR reverts the changes in #2281 as per what was discussed offline, due to its corresponding backend PR source-academy/backend#914 not being merged.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Code quality improvements

How to test

Everything should still work. Compare the diffs between the two PRs; though lots of refactors have been done since, they should still make sense.

Checklist

• I have tested this code
• I have updated the documentation

[coveralls]

Pull Request Test Coverage Report for Build 7890237329

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.2%) to 37.396%

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Files with Coverage Reduction	New Missed Lines	%
src/pages/academy/Academy.tsx	1	0.0%

Totals
Change from base Build 7890035645:	0.2%
Covered Lines:	5739
Relevant Lines:	14438

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💛 - Coveralls