refactor!: move common/lib/capa/capa to xmodule/capa

As part of dissolving our sub-projects in edx-platform, we are moving this package under the xmodule directory.
We have fixed all the occurences of import of this package and also fixed all documents related references.
This might break your platform if you have any reference of `import capa` or `from capa import` in your codebase or in any Xblock.

Ref: https://openedx.atlassian.net/browse/BOM-2582

.github/workflows/unit-test-shards.json

@@ -261,12 +261,6 @@
     ]
   },
   "common-2": {
-    "settings": "lms.envs.test",
-    "paths": [
-      "common/lib/"
-    ]
-  },
-  "common-3": {
     "settings": "cms.envs.test",
     "paths": [
       "common/djangoapps/"

.github/workflows/unit-tests.yml

@@ -31,7 +31,6 @@ jobs:
             "cms-2",
             "common-1",
             "common-2",
-            "common-3",
             "xmodule-1"
         ]
 
@@ -62,7 +61,7 @@ jobs:
       - name: install requirements
         run: |
           sudo pip install -r requirements/pip.txt
-          sudo pip install -r requirements/edx/testing.txt
+          sudo pip install --exists-action='w' -r requirements/edx/testing.txt
           if [[ "${{ matrix.django-version }}" == "pinned" ]]; then
             sudo pip install -r requirements/edx/django.txt
           else

.github/workflows/verify-gha-unit-tests-count.yml

@@ -18,7 +18,7 @@ jobs:
       - name: install requirements
         run: |
           sudo pip install -r requirements/pip.txt
-          sudo pip install -r requirements/edx/testing.txt
+          sudo pip install --exists-action='w' -r requirements/edx/testing.txt
 
       - name: verify unit tests count
         uses: ./.github/actions/verify-tests-count