feat: detect changes in sources

[AtomicFS]

• few fixes (mostly small stuff)
• speed up filesystem.DirTree (I just happened to stumble upon it)
• add functions to detect changes in files
  • add new filesystem functions which can detect changes in files base on time-stamps
  • since we work with large projects, such as Linux Kernel, this detection should be as fast as possible
  • to make it fast, we solely rely on time, no hashing
  • the idea is that firmware-action will create a time-stamp file at the end of each execution (for each target)
  • at the start of each execution firmware-action will load time-stamp file from previous execution and check if any file in sources is newer that the saved time-stamp
  • the detection function is lazy, and will return on first positive match
  • if the no file in sources is newer, target should be considered up-to-date and skipped
• add the ability to detect changes in sources
• in addition, the dagger setup was moved so now the loop for up-to-date module is much faster
• prettify summary table

Summary before:

[INFO   ] Build summary:
uroot-example: Skipped
linux-example-with-uroot: Skipped
coreboot-example-with-linuxboot: Skipped

Summary now:

[INFO   ] Build summary:
+---------------------------------+------------+
| MODULE                          | STATUS     |
+---------------------------------+------------+
| uroot-example                   | Up-to-date |
| linux-example-with-uroot        | Up-to-date |
| coreboot-example-with-linuxboot | Up-to-date |
+---------------------------------+------------+

fixes #441

[AtomicFS]

@MDr164 I just made one small change - when the givenTime is zero (for example when there is no timestamp file), it behaves like the target it is up-to-date. This is mostly for convenience in CI.

up-to-date just means that if the output directory exists, it will not re-build.

[AtomicFS]

No to toot my own horn, but I like that this is actually much faster than Taskfile. They go the slow way file-by-file, which this does the directory at the time. And with minimal reads too thanks to the WalkDir (improvement over Walk).

Fully checked out uroot, linux and coreboot are checked in 0.5 seconds.

[AtomicFS]

@MDr164 do you have time for review?

[MDr164]

Looks mostly fine, just some minor comments