[FIX] Address performance issues in SPARQL query

[surchs]

• Closes #307
• Closes #306

Changes proposed in this pull request:

• fix typo in template (#306)
• explicit naming of imaging session
• simplify formatting for readability

Checklist

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• [x] PR has an interpretable title with a prefix ([ENH], [FIX], [REF], [TST], [CI], [MNT], [INF], [MODEL], [DOC]) (see our Contributing Guidelines for more info)
• [x] PR has a label for the release changelog or skip-release (to be applied by maintainers only)
• [x] PR links to GitHub issue with mention Closes #XXXX
• [ ] Tests pass
• [x] Checks pass

For new features:

• [ ] Tests have been added

For bug fixes:

• [ ] There is at least one test that would fail under the original bug conditions.

[coveralls]

Pull Request Test Coverage Report for Build 8693379517

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 99.788%

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Totals
Change from base Build 8670779129:	0.0%
Covered Lines:	940
Relevant Lines:	942

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💛 - Coveralls

[alyssadai]

Please update the default query file as well, in docs/!

[alyssadai]

https://github.com/neurobagel/api?tab=readme-ov-file#the-default-neurobagel-sparql-query

[surchs]

:rocket: PR was released in v0.2.1 :rocket: