Implement a 100 Ada hard-coded commit limit in the hydra-node

[v0d1ch]

Why

In the light of our goal of getting Hydra to Mainnet we would also like to prevent our users to shoot themselves in the foot with a mannet gun ™️ .

To acomodate this we want to impose a limit on the number of Ada you can commit to a hydra head on mainnet so if anything doesn't go as planned at least we are not loosing too much crypto.

What

Introduce a hardcoded limit of 100 Ada when constructing a commit tx IF the network is mainnet.

Additionally we might want to also have a log (or error) for this case when someone wants to commit more than 100 ada just to keep users aware of this limit.