tests/format/junctions.py: Major refactor

This commit refactors the junctions test to use more parameterization
and to remove copy_subproject(), using statically committed data as
much as possible.

This is because copy_subproject() causes data to be shared among tests
in such a way that when such data get's modified, it easily causes
unintended side effects on adjacent test cases, better to keep this
data separate.

Overview of changes:

  * Remove copy_subproject()

  * Split up test data into case specific directories, sometimes
    reusing a directory among various related tests

  * Use @pytest.mark.parameterize() as much as possible for better
    coverage and more clearly expressed test cases

  * Adds update_project() to modify a project.conf inline, as is
    done in some other tests like tests/plugins/loading.py

  * Removes tests related to junction name coalescing, this feature
    will be removed later in this branch and other tests related
    to junction overrides will replace these.

  * Removes some redundant tests

  * Removes a comment about how junction name coalescing can cause
    errors when trying to open a junction but the project.conf is
    missing. We continue to test missing project.conf files in a
    variety of scenarios, but the comment will be rendered irrelevant
    with the removal of junction name coalescing.

  * Change the git related tests to use tar instead, this serves
    the same purpose, but tar will remain a core plugin in BuildStream 2.

1 files changed, 0 insertions, 8 deletions

diff --git a/tests/format/junctions/inconsistent-names/junctionA/project.conf b/tests/format/junctions/inconsistent-names/junctionA/project.conf
deleted file mode 100644
index 8af914819..000000000
--- a/tests/format/junctions/inconsistent-names/junctionA/project.conf
+++ /dev/null
@@ -1,8 +0,0 @@
-# Unique project name
-name: projectA
-
-# Minimum required BuildStream version
-min-version: 2.0
-
-# Subdirectory where elements are stored
-element-path: elements