pyproject: add extra for each CLI command

Add extras for CLI commands and move some dependencies that are only
used by them into those extras. This allows to install only a subset
of dependencies for only the command one needs (in CI for example).

To make testing easier there also exists a "all" extra which installs
everything.

Author: lazka

.github/workflows/test.yml

@@ -22,7 +22,7 @@ jobs:
     - name: Install dependencies
       run: |
         pipx install poetry
-        poetry install
+        poetry install -Eall
 
     - name: Run tests
       run: |

README.md

@@ -11,3 +11,11 @@ CI commands:
 * `msys2-srcinfo-cache`: Maintains srcinfo data for all packages in a git repo
 * `msys2-pypi-cache`: Maintains a pypi metadata cache for all packages
 * `msys2-sbom`: Generate a SBOM file for all packages
+
+Installation:
+
+For every CLI command there exists a Python package extra with the same name:
+
+* `pip install msys2-devtools[sbom]`
+
+In addition there exists an `all` extra that installs all dependencies.