Add an option to convert with tainted kernel modules

convert2rhel fails currently when emc storage kernel modules are loaded.

[09/20/2023 23:59:10] DEBUG - Calling command 'grep ( /proc/modules'
emcpdm 47855 0 - Live 0xffffffffc02d9000 (POE)
emcpgpx 24016 1 emcpdm, Live 0xffffffffc01b9000 (POE)
emcpmpx 363259 0 - Live 0xffffffffc0749000 (POE)
emcp 1297946 9 emcpdm,emcpgpx,emcpmpx, Live 0xffffffffc0c28000 (POE)
ERROR - (ERROR) TAINTED_KMODS.TAINTED_KMODS_DETECTED: Tainted kernel modules detected:
  emcpdm
  emcpgpx
  emcpmpx
  emcp
Third-party components are not supported per our software support policy:
 https://access.redhat.com/third-party-software-support
Prevent the modules from loading by following https://access.redhat.com/solutions/41278 and run convert2rhel again to continue with the conversion.  

 
There is a kmods_to_ignore option in /usr/share/convert2rhel/configs/*.cfg  but it only applies only to another check that compares the loaded modules with those available in RHEL.
 
We are requesting a way to allow these tainted kernel modules as this customer requires them for their storage and will use them after the conversion as well. 

Acceptance criteria:

• the tainted kmod check is made an overridable inhibitor
• the leapp folks are asked if leapp has an inhibitor that would prevent a system from being upgraded - if they have, we add a warning that when overriding the check they wouldn't be able to proceed with the upgrade after the conversion
• if tainted modules are detected, the report message states that overriding the check is dangerous and they should make sure they have a system backup
• The message is improved to not scare customers who don't know what a tainted kernel is
  • A link to an online document explaining what a tainted kernel is added
  • we've seen quite a few people (mostly SAs) on Slack and GChat being taken by surprise what does this inhibitor means and what should they do - we need to be much clearer