89339d14607434b33cfa343dc75877b62b1dfe0e tests: Add test for loadblock option (Fabian Jahr)
Pull request description:
Fixes #17019 Was initially part of #17044 but as the test got larger it made sense to split it into its own commit as suggested in #17019 . This is testing the `-loadblock` option by using the scripts in `contrib/linearize` to generate a `bootstrap.dat` file and starting a disconnected node with it. So it is also testing the linearize scripts which were untested before and needed to be made available for the CI environment, hence they are added to `DIST_CONTRIB` in `Makefile.am`.
Backport of Core PR17091