The Track itself caches the Samples after each processing step which
allows it to be queried without the need to process it every time.
This result is queried by the WaveWidget which then caches the result to
prevent unnecessary heap allocations every paint event.
Removes the Sample struct inside Piano and replaces it with the struct
from LibDSP.
It automatically scales the height of the wave depending on the maximum
amplitude, as the Samples now contain floats and not integers.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
