Fix bug with trailing slashes in xdmod_host.

[RodneyCodess]

Description

This PR fixes a bug when trailing slashes are in the xdmod_host parameter. For an example:

with DataWarehouse('https://xdmod.access-ci.org/') as dw:
    dw.get_raw_data(
        duration=('2024-01-01', '2024-01-01'),
        realm='Jobs',
    )

Because this 'https://xdmod.access-ci.org/' has a trailing slash that results in a
RuntimeError: Error 404: No route found for "GET //rest/v1/warehouse/export/realms".

Tests performed

This PR adds an automated integration test that runs every method in the API with 'https://xdmod.access-ci.org/'. In order to make that work this PR also adds the ability to pass in an invalid URL to dw_methods.

This PR also updates the sample values used when testing, specifically 'duration' so that fewer raw data are requested and 'show_progress' so that the output is easier to read.

This PR also fixes multiple style issues and reduces duplicated code.

Types of changes

• Refactoring / documentation update (non-breaking change which does not change functionality)
• 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 change)

Checklist:

• CHANGELOG.md has been updated
• The milestone is set correctly on the pull request
• The appropriate labels have been added to the pull request
• Running the automated tests (see docs/developing.md) produces no errors
• Updates have been made to the xdmod-notebooks repository as necessary, and the notebooks all run successfully