Instead of smashing together all the samples into a single timeline,
make one per process and put them all in a ScrollableContainerWidget.
This makes it much easier to see which processes were active and when.
No timeline is displayed for processes with zero samples in the profile.
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 *
Currently, there is no way to know when in a profile's duration a
sample was taken. This commit adds a basic timestamp to the timeline
widget, and a black bar to show where the cursor is hovering over.
