ENH: use multi_file_day = True for ICON IVM data

[jklenzing]

Description

Addresses #87

ICON IVM data files are slightly misaligned with UT, including about 30s of the previous day and dropping the last 30s. The multi_file_day option corrects for this and allows one complete day to be loaded when requested.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Assuming registration and download,

import pysat
ivm = pysat.Instrument('icon', 'ivm', inst_id='a')
ivm.load(2020, 1)

Inspection of data should align with day boundaries.

Test Configuration

• Operating system: Mac OS X 10.15.7
• Version number: python 3.8.11

Checklist:

• Make sure you are merging into the develop (not main) branch
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• Add a note to CHANGELOG.md, summarizing the changes
• [na] Update zenodo.json file for new code contributors

[rstoneback]

+1

[rstoneback]

Thanks @jklenzing!