[harmony] components of ipx.variables and ipx.is2ref likely impacted by transition from EGI

[JessicaS11]

A list of the components in the ipx.Variables module most likely to be impacted by this transition include:

• __init__ (in that it directly calls the below functions in ipx.is2ref

A list of the components in the ipx.is2ref module most likely impacted by this transition:

• _get_custom_options() (which calls on a capability_url that has an on-prem EGI endpoint)

[JessicaS11]

We may be able to use this new feature in earthaccess to address the is2ref._get_custom_options() use of an egi capability url.