PY-47962 Start-match non-imported module names in completion

This way we further reduce the number of irrelevant completion items suggested
effectively in every expression context, e.g. not suggesting "parser" and
"calendar" modules for the "ar" prefix, only something like "argparse" or
"array". The same applies to the completion of attributes with unresolved
qualifiers.

GitOrigin-RevId: 7a58053c4744c3d0066c379a4f190ffd09bfabd1

python/testData/completion/notImportedQualifiedName/AttributesOfModulesWithMiddleMatchNotSuggested/fb.py

@@ -0,0 +1 @@
+var = 42

python/testData/completion/notImportedQualifiedName/AttributesOfModulesWithMiddleMatchNotSuggested/fb_util.py

@@ -0,0 +1 @@
+var = 42

python/testData/completion/notImportedQualifiedName/AttributesOfModulesWithMiddleMatchNotSuggested/foo_bar.py

@@ -0,0 +1 @@
+var = 42

python/testData/completion/notImportedQualifiedName/AttributesOfModulesWithMiddleMatchNotSuggested/foobar.py

@@ -0,0 +1 @@
+var = 42

python/testData/completion/notImportedQualifiedName/AttributesOfModulesWithMiddleMatchNotSuggested/main.py

@@ -0,0 +1 @@
+fb.va<caret>

python/testData/completion/notImportedQualifiedName/AttributesOfModulesWithMiddleMatchNotSuggested/mod_fb.py

@@ -0,0 +1 @@
+var = 42

python/testData/completion/notImportedQualifiedName/AttributesOfModulesWithMiddleMatchNotSuggested/mod_foo_bar.py

@@ -0,0 +1 @@
+var = 42

python/testData/completion/notImportedQualifiedName/ModuleNamesWithMiddleMatchNotSuggested/main.py

@@ -0,0 +1 @@
+fb<caret>