feat(fetcher): implement SearchBasedFetcher for ScienceDirect using scopus search API

[Siva-Sai22]

Closes #14421

Implemented web search capability for ScienceDirect by integrating the Scopus Search API, since the ScienceDirect Search API requires institutional access that most users don't have. Added a new ScopusQueryTransformer to convert JabRef search queries to Scopus query syntax, and rewrote the ScienceDirect class to implement PagedSearchBasedParserFetcher interface, enabling paginated search results with proper JSON response parsing, this allows users to search academic literature via the "Web search" feature in JabRef, which was previously not available for ScienceDirect.

Steps to test

• Go to settings -> preferences -> websearch.
• Add the ScienceDirect API key and test it.
• Then search using the ScienceDirect (Example query: Einstein)

Mandatory checks

• I own the copyright of the code submitted and I license it under the MIT license
• I manually tested my changes in running JabRef (always required)
• I added JUnit tests for changes (if applicable)
• I added screenshots in the PR description (if change is visible to the user)
• I described the change in CHANGELOG.md in a way that is understandable for the average user (if change is visible to the user)
• I checked the user documentation: Is the information available and up to date? If not, I created an issue at https://github.com/JabRef/user-documentation/issues or, even better, I submitted a pull request updating file(s) in https://github.com/JabRef/user-documentation/tree/main/en.

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[koppor]

According to https://dev.elsevier.com/technical_documentation.html Scopus is not ScienceDirect.

I see two options:

1. To avoid confusion, ScienceDirect should be renamed to Elsevier. But then, we have a "big ball of mud", because the methods in that class are not coupled, but only semnatically correlated
2. Add new functionality to Scopus - this should make maintainence easier. This fetcher should be added to the list of fetchers in the "Web Search" prefernces

Please do option 2 to have the fetcher class small.

• API key should renamed from "Scopus" to "Esevier", since it covers both.

---

Future work: Split up API key configuration and fetcher enablement.

[koppor]

There must be a method to convert an inputstream to a JSON object directly. But maybe, not mit dem JSONObject.

[Siedlerchr]

** JSONObject response = JsonReader.toJsonObject(inputStream);
**

[koppor]

Another view - from

[Siva-Sai22]

• API key should renamed from "Scopus" to "Esevier", since it covers both.

@koppor
But the ScienceDirect is accessing the api key using the FETCHER_NAME (ScienceDirect). If we rename it to Esevier we have to change the fetcher name also
importerPreferences.getApiKey(getName())

I think it would be better to take a scopus api key also.