fix: maven use groupId:artifactId for package name concatenation (#6352)

Second part of #6327 to fix the Maven package naming. This pull request includes:
* Changing the group and artifact IDs from being separated by `-` to `:` as suggested by [Maven](https://maven.apache.org/pom.html#Maven_Coordinates).
* Making Maven package names case-sensitive
* Migrating the database to:
  * Handle collisions of package names (e.g., groupId: foo- with artifactId: bar and groupId: foo with artifactId: -bar) by moving them into their own packages.
  * Fix the missing group ID issue (#6329).
  * Update  lower_name to match the name value for maven pkgs to make it case-sensetive.

## Checklist

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### Tests

- I added test coverage for Go changes...
  - [x] in their respective `*_test.go` for unit tests.
  - [x] in the `tests/integration` directory if it involves interactions with a live Forgejo server.
- I added test coverage for JavaScript changes...
  - [ ] in `web_src/js/*.test.js` if it can be unit tested.
  - [ ] in `tests/e2e/*.test.e2e.js` if it requires interactions with a live Forgejo server (see also the [developer guide for JavaScript testing](https://codeberg.org/forgejo/forgejo/src/branch/forgejo/tests/e2e/README.md#end-to-end-tests)).

### Documentation

- [ ] I created a pull request [to the documentation](https://codeberg.org/forgejo/docs) to explain to Forgejo users how to use this change.
- [x] I did not document these changes and I do not expect someone else to do it.

### Release notes

- [ ] I do not want this change to show in the release notes.
- [x] I want the title to show in the release notes with a link to this pull request.
- [ ] I want the content of the `release-notes/<pull request number>.md` to be be used for the release notes instead of the title.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/6352
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Julian Schlarb <julian.schlarb@denktmit.de>
Co-committed-by: Julian Schlarb <julian.schlarb@denktmit.de>

models/packages/package_file.go

@@ -87,8 +87,8 @@ func GetFileForVersionByID(ctx context.Context, versionID, fileID int64) (*Packa
 	return pf, nil
 }
 
-// GetFileForVersionByName gets a file of a version by name
-func GetFileForVersionByName(ctx context.Context, versionID int64, name, key string) (*PackageFile, error) {
+// GetFileForVersionByNameMatchCase gets a file of a version by name
+func GetFileForVersionByNameMatchCase(ctx context.Context, versionID int64, name, key string) (*PackageFile, error) {
 	if name == "" {
 		return nil, ErrPackageFileNotExist
 	}
@@ -97,7 +97,7 @@ func GetFileForVersionByName(ctx context.Context, versionID int64, name, key str
 
 	has, err := db.GetEngine(ctx).Where(builder.Eq{
 		"version_id":    versionID,
-		"lower_name":    strings.ToLower(name),
+		"lower_name":    name,
 		"composite_key": key,
 	}).Get(pf)
 	if err != nil {
@@ -109,6 +109,11 @@ func GetFileForVersionByName(ctx context.Context, versionID int64, name, key str
 	return pf, nil
 }
 
+// GetFileForVersionByName gets a file of a version by name
+func GetFileForVersionByName(ctx context.Context, versionID int64, name, key string) (*PackageFile, error) {
+	return GetFileForVersionByNameMatchCase(ctx, versionID, strings.ToLower(name), key)
+}
+
 // DeleteFileByID deletes a file
 func DeleteFileByID(ctx context.Context, fileID int64) error {
 	_, err := db.GetEngine(ctx).ID(fileID).Delete(&PackageFile{})