Fully support module alias or symbolic version icase resolution

[xdelaruelle]

Icase implementation, introduced in Modules 4.4, should be refined to fully support module alias and symbolic version. Following cases are currently lacking support:

• indirect alternative names, expressed in an icase manner, are not reported among alternative names
• symbolic version targeting a modulefile in an icase manner, is not reported through avail results
• when 1 alias matches exactly a module name and another alias matches also this module but in an icase manner, this second alias is not reported among alternative names

setModuleResolution procedure should be reworked to achieve a complete icase support on module aliases and symbolic versions.