True if the Hacknet Node’s cache level is successfully upgraded, false otherwise.
## Remarks
RAM cost: 0 GB
This function is only applicable for Hacknet Servers (the upgraded version of a Hacknet Node).
Tries to upgrade the specified Hacknet Server’s cache n times.
Returns true if it successfully upgrades the Server’s cache n times, or if it purchases some positive amount and the Server reaches its max cache level.