feat(migrations): add migration from Bitbucket Server (Data Center) (#39913)

Add migration from Bitbucket Server (Data Center). It has no issues,
wiki, milestones or releases, so those are not offered.

Migrated: git data with tags and LFS, and pull requests with state,
draft flag, merge commit/base, comments, approvals and inline code
comments including resolved threads. Multi-line ranges become a `Lines
a-b:` text prefix, as Gitea anchors code comments to one line. Auth is
an HTTP access token (personal, project or repository) or
username/password; 429 responses are retried.

Changes outside the downloader:
- `ReviewComment.Resolved`, applied by the uploader.
- The uploader creates a fork PR's head branch from its head commit when
already in the repository, instead of fetching the fork (Bitbucket keeps
it in `refs/pull-requests/<id>/from`; private forks need credentials).

Tested with unit tests, responses recorded from Bitbucket 10.5.1, and an
end-to-end migration. Independent of
https://github.com/go-gitea/gitea/pull/38607 (Bitbucket Cloud); the
service type enum value needs adjusting for whichever lands second.

---------

Co-authored-by: bircni <bircni@icloud.com>

templates/repo/migrate/bitbucketserver.tmpl

@@ -0,0 +1,54 @@
+{{template "base/head" .}}
+<div role="main" aria-label="{{.Title}}" class="page-content repository new migrate">
+	<div class="ui container medium-width">
+		<h3 class="ui top attached header">
+			{{ctx.Locale.Tr "repo.migrate.migrate" .service.Title}}
+		</h3>
+		<div class="ui attached segment">
+			{{template "base/alert" .}}
+			<form class="ui form left-right-form form-fetch-action" action="{{.Link}}" method="post">
+				{{template "repo/migrate/common-init" (dict "ServiceType" .service)}}
+				{{template "repo/migrate/variants" .}}
+
+				<div class="inline required field">
+					<label>{{ctx.Locale.Tr "repo.migrate.clone_address"}}</label>
+					<input name="clone_addr" autofocus required>
+					<span class="help">
+					{{ctx.Locale.Tr "repo.migrate.clone_address_desc"}}{{if .ContextUser.CanImportLocal}} {{ctx.Locale.Tr "repo.migrate.clone_local_path"}}{{end}}
+					</span>
+				</div>
+
+				<div class="inline field">
+					<label>{{ctx.Locale.Tr "username"}}</label>
+					<input name="auth_username">
+				</div>
+				<div class="inline field">
+					<label>{{ctx.Locale.Tr "password"}}</label>
+					<input name="auth_password" type="password">
+				</div>
+				<div class="inline field">
+					<label>{{ctx.Locale.Tr "access_token"}}</label>
+					<input name="auth_token" type="password" autocomplete="new-password">
+					<span class="help">{{ctx.Locale.Tr "repo.migrate.bitbucketserver.token_desc"}}</span>
+				</div>
+
+				{{template "repo/migrate/common-options" .}}
+
+				<div id="migrate_items">
+					<div class="inline field">
+						<label>{{ctx.Locale.Tr "repo.migrate_items"}}</label>
+						<div class="ui checkbox">
+							<input name="pull_requests" type="checkbox">
+							<label>{{ctx.Locale.Tr "repo.migrate_items_pullrequests"}}</label>
+						</div>
+					</div>
+				</div>
+
+				<div class="divider"></div>
+
+				{{template "repo/migrate/common-migrated-repo"}}
+			</form>
+		</div>
+	</div>
+</div>
+{{template "base/footer" .}}

templates/repo/migrate/migrate.tmpl

@@ -10,6 +10,8 @@
 							{{svg "octicon-mark-github" 184 "tw-p-4"}}
 						{{else if eq .Name "gitlab"}}
 							{{svg "gitea-gitlab" 184 "tw-p-4"}}
+						{{else if eq .Name "bitbucketserver"}}
+							{{svg "gitea-bitbucket" 184 "tw-p-4"}}
 						{{else if eq .Name "gitbucket"}}
 							{{svg "gitea-gitbucket" 184 "tw-p-4"}}
 						{{else}}
@@ -17,7 +19,7 @@
 						{{end}}
 						<div class="content">
 							<div class="header tw-text-center">
-								{{.Title}}
+								{{.ProviderTitle}}
 							</div>
 							<div class="description tw-text-center tw-text-balance">
 								{{ctx.Locale.Tr (printf "repo.migrate.%s.description" .Name)}}

templates/repo/migrate/variants.tmpl

@@ -0,0 +1,10 @@
+{{if gt (len .ServiceVariants) 1}}
+<div class="inline field">
+	<label>{{ctx.Locale.Tr "repo.migrate.hosting"}}</label>
+	<div class="ui compact small menu">
+		{{range .ServiceVariants}}
+		<a class="item {{Iif (eq . $.service) "active"}}" href="{{AppSubUrl}}/repo/migrate?service_type={{.}}&org={{$.ContextUser.ID}}&mirror={{$.mirror}}">{{ctx.Locale.Tr (printf "repo.migrate.%s.variant" .Name)}}</a>
+		{{end}}
+	</div>
+</div>
+{{end}}

templates/swagger/v1-openapi3.generated.json

@@ -7988,7 +7988,8 @@
               "onedev",
               "gitbucket",
               "codebase",
-              "codecommit"
+              "codecommit",
+              "bitbucketserver"
             ],
             "type": "string",
             "x-go-name": "Service"

templates/swagger/v1-swagger.generated.json

@@ -31829,7 +31829,8 @@
             "onedev",
             "gitbucket",
             "codebase",
-            "codecommit"
+            "codecommit",
+            "bitbucketserver"
           ],
           "x-go-name": "Service"
         },