fix rest assured conflicts, fix test cases for signed urls with filenames

Description:

Issue: #79 (closed) Fixed related to RestAssured libs conflicts:

    java.lang.NoClassDefFoundError: Could not initialize class io.restassured.RestAssured
	at org.opengroup.osdu.file.util.test.RestAssuredClient.<init>(RestAssuredClient.java:30)
	at org.opengroup.osdu.file.util.test.HttpClientFactory.getInstance(HttpClientFactory.java:8)
	at org.opengroup.osdu.file.stepdefs.FileStepDef_GET.lambda$new$1(FileStepDef_GET.java:76)

Fix assertion for a test case for file download with preserving filename.
Fix assertion for invalid file source test.
Ignore the test to test special characters in FileSourceInfo.Name since there are no checks in the File service for such cases.

How to test:

Does functionality was tested and how?

Changes include:

• Refactor (a non-breaking change that improves code maintainability).
• Bugfix (a non-breaking change that solves an issue).
• New feature (a non-breaking change that adds functionality).
• Breaking change (a change that is not backward-compatible and/or changes current functionality).

Changes in:

• Common code

Dev Checklist:

• Added Unit Tests, wherever applicable.
• Updated the Readme, if applicable.
• Existing Tests pass
• Verified functionality locally
• Self Reviewed my code for formatting and complex business logic.