Warmup SharedTrieCache at startup

[alexggh]

Add logic at the node level, that based on the runtime configuration/maybe cli flag, decides that entire state needs to fit into memory, warms up the SharedTrieCache and performs some sanity checks to confirm memory usage is within reasonable bounds.

In case memory is insufficient or we are running low on it the node should abort graciously.

[bkchr]

Add logic at the collator level

Just general node level.

Not sure we need some sanity checks. As we read the state, we could warn when we see that the memory usage is too high or abort "nicely".

[alexggh]

Not sure we need some sanity checks. As we read the state, we could warn when we see that the memory usage is too high or abort "nicely".

Yes, the end result should be either the node succeeded warming the SharedTrieCache and the spare memory is still in some reasonable bounds and if either can't fit the entire state into the SharedTrieCache or if it is running low on memory post warming it should abort nicely.

Updated the description to make it more clear.