Support repo license (#24872)

Close #278
Close #24076

## Solutions:
- Use
[google/licenseclassifier](https://github.com/google/licenseclassifier/)
Test result between
[google/licensecheck](https://github.com/google/licensecheck) and
[go-license-detector](https://github.com/go-enry/go-license-detector):
https://github.com/go-gitea/gitea/pull/24872#issuecomment-1560361167
Test result between
[google/licensecheck](https://github.com/google/licensecheck) and
[google/licenseclassifier](https://github.com/google/licenseclassifier/):
https://github.com/go-gitea/gitea/pull/24872#issuecomment-1576092178
- Generate License Convert Name List to avoid import license templates
with same contents
Gitea automatically get latest license data from[
spdx/license-list-data](https://github.com/spdx/license-list-data).
But unfortunately, some license templates have same contents. #20915
[click here to see the
list](https://github.com/go-gitea/gitea/pull/24872#issuecomment-1584141684)
So we will generate a list of these license templates with same contents
and create a new file to save the result when using `make
generate-license`. (Need to decide the save path)
- Save License info into a new table `repo_license`
Can easily support searching repo by license in the future.

## Screen shot
Single License:

![image](https://github.com/go-gitea/gitea/assets/18380374/41260bd7-0b4c-4038-8592-508706cffa9f)

Multiple Licenses:

![image](https://github.com/go-gitea/gitea/assets/18380374/34ce2f73-7e18-446b-9b96-ecc4fb61bd70)

Triggers:
- [x] Push commit to default branch
- [x] Create repo
- [x] Mirror repo
- [x] When Default Branch is changed, licenses should be updated

Todo:
- [x] Save Licenses info in to DB when there's a change to license file
in the commit
- [x] DB Migration
- [x] A nominal test?
- [x] Select which library to
use(https://github.com/go-gitea/gitea/pull/24872#issuecomment-1560361167)
- [x] API Support
- [x] Add repo license table
- ~Select license in settings if there are several licenses(Not
recommended)~
- License board(later, not in this PR)

![image](https://github.com/go-gitea/gitea/assets/18380374/2c3c3bf8-bcc2-4c6d-8ce0-81d1a9733878)

---------

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Denys Konovalov <kontakt@denyskon.de>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: 6543 <m.huber@kithara.com>
Co-authored-by: a1012112796 <1012112796@qq.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.com>

routers/private/default_branch.go

@@ -12,6 +12,7 @@ import (
 	"code.gitea.io/gitea/modules/gitrepo"
 	"code.gitea.io/gitea/modules/private"
 	gitea_context "code.gitea.io/gitea/services/context"
+	repo_service "code.gitea.io/gitea/services/repository"
 )
 
 // SetDefaultBranch updates the default branch
@@ -36,5 +37,15 @@ func SetDefaultBranch(ctx *gitea_context.PrivateContext) {
 		})
 		return
 	}
+
+	if err := repo_service.AddRepoToLicenseUpdaterQueue(&repo_service.LicenseUpdaterOptions{
+		RepoID: ctx.Repo.Repository.ID,
+	}); err != nil {
+		ctx.JSON(http.StatusInternalServerError, private.Response{
+			Err: fmt.Sprintf("Unable to set default branch on repository: %s/%s Error: %v", ownerName, repoName, err),
+		})
+		return
+	}
+
 	ctx.PlainText(http.StatusOK, "success")
 }

routers/private/hook_post_receive.go

@@ -278,10 +278,19 @@ func HookPostReceive(ctx *gitea_context.PrivateContext) {
 
 			branch := refFullName.BranchName()
 
-			// If our branch is the default branch of an unforked repo - there's no PR to create or refer to
-			if !repo.IsFork && branch == baseRepo.DefaultBranch {
-				results = append(results, private.HookPostReceiveBranchResult{})
-				continue
+			if branch == baseRepo.DefaultBranch {
+				if err := repo_service.AddRepoToLicenseUpdaterQueue(&repo_service.LicenseUpdaterOptions{
+					RepoID: repo.ID,
+				}); err != nil {
+					ctx.JSON(http.StatusInternalServerError, private.Response{Err: err.Error()})
+					return
+				}
+
+				// If our branch is the default branch of an unforked repo - there's no PR to create or refer to
+				if !repo.IsFork {
+					results = append(results, private.HookPostReceiveBranchResult{})
+					continue
+				}
 			}
 
 			pr, err := issues_model.GetUnmergedPullRequest(ctx, repo.ID, baseRepo.ID, branch, baseRepo.DefaultBranch, issues_model.PullRequestFlowGithub)