Remove usage of SSC token

[jfrank-summit]

SSC was the original native token for the network, but this is no longer valid. This should be replaced with either "native token" or some other generic term or with AI3. @vedhavyas do you have thoughts on how we should approach this?

[vedhavyas]

There are two places

• Protocol specs
• Monorepo

Both can be replaced with AI3 as there are just placeholder names.
We already put the correct token name in the chainspec so should not affect the chains as well