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](41260bd7-0b4c-4038-8592-508706cffa9f)

Multiple Licenses:

![image](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](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/web/repo/commit.go

@@ -29,7 +29,7 @@ import (
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/services/context"
 	"code.gitea.io/gitea/services/gitdiff"
-	git_service "code.gitea.io/gitea/services/repository"
+	repo_service "code.gitea.io/gitea/services/repository"
 )
 
 const (
@@ -101,7 +101,7 @@ func Commits(ctx *context.Context) {
 	pager := context.NewPagination(int(commitsCount), pageSize, page, 5)
 	pager.SetDefaultParams(ctx)
 	ctx.Data["Page"] = pager
-
+	ctx.Data["LicenseFileName"] = repo_service.LicenseFileName
 	ctx.HTML(http.StatusOK, tplCommits)
 }
 
@@ -218,6 +218,8 @@ func SearchCommits(ctx *context.Context) {
 	}
 	ctx.Data["Username"] = ctx.Repo.Owner.Name
 	ctx.Data["Reponame"] = ctx.Repo.Repository.Name
+	ctx.Data["RefName"] = ctx.Repo.RefName
+	ctx.Data["LicenseFileName"] = repo_service.LicenseFileName
 	ctx.HTML(http.StatusOK, tplCommits)
 }
 
@@ -263,12 +265,12 @@ func FileHistory(ctx *context.Context) {
 	pager := context.NewPagination(int(commitsCount), setting.Git.CommitsRangeSize, page, 5)
 	pager.SetDefaultParams(ctx)
 	ctx.Data["Page"] = pager
-
+	ctx.Data["LicenseFileName"] = repo_service.LicenseFileName
 	ctx.HTML(http.StatusOK, tplCommits)
 }
 
 func LoadBranchesAndTags(ctx *context.Context) {
-	response, err := git_service.LoadBranchesAndTags(ctx, ctx.Repo, ctx.PathParam("sha"))
+	response, err := repo_service.LoadBranchesAndTags(ctx, ctx.Repo, ctx.PathParam("sha"))
 	if err == nil {
 		ctx.JSON(http.StatusOK, response)
 		return