<!-- Thanks for sending a pull request! Here are some tips for you:
1. 如果这是你的第一次，请阅读我们的贡献指南：<https://github.com/halo-dev/halo/blob/master/CONTRIBUTING.md>。
1. If this is your first time, please read our contributor guidelines: <https://github.com/halo-dev/halo/blob/master/CONTRIBUTING.md>.
2. 请根据你解决问题的类型为 Pull Request 添加合适的标签。
2. Please label this pull request according to what type of issue you are addressing, especially if this is a release targeted pull request.
3. 请确保你已经添加并运行了适当的测试。
3. Ensure you have added or ran the appropriate tests for your PR.
-->
#### What type of PR is this?
/kind feature
/milestone 2.0
<!--
添加其中一个类别：
Add one of the following kinds:
/kind bug
/kind cleanup
/kind documentation
/kind feature
/kind optimization
适当添加其中一个或多个类别（可选）：
Optionally add one or more of the following kinds if applicable:
/kind api-change
/kind deprecation
/kind failing-test
/kind flake
/kind regression
-->
#### What this PR does / why we need it:
增加附件管理的功能，适配 https://github.com/halo-dev/halo/pull/2354
#### Which issue(s) this PR fixes:
Fixes https://github.com/halo-dev/halo/issues/2330
<!--
PR 合并时自动关闭 issue。
Automatically closes linked issue when PR is merged.
用法：`Fixes #<issue 号>`，或者 `Fixes (粘贴 issue 完整链接)`
Usage: `Fixes #<issue number>`, or `Fixes (paste link of issue)`.
-->
#### Screenshots:
None
<!--
如果此 PR 有 UI 的改动，最好截图说明这个 PR 的改动。
If there are UI changes to this PR, it is best to take a screenshot to illustrate the changes to this PR.
eg.
Before:
After:
-->
#### Special notes for your reviewer:
todo list:
- [x] 根据分组筛选附件列表。
- [x] 非图片文件支持显示占位图。
- [x] 完善选择附件组件。
- [ ] ~~附件引用关系查询。~~
#### Does this PR introduce a user-facing change?
<!--
如果当前 Pull Request 的修改不会造成用户侧的任何变更，在 `release-note` 代码块儿中填写 `NONE`。
否则请填写用户侧能够理解的 Release Note。如果当前 Pull Request 包含破坏性更新（Break Change），
Release Note 需要以 `action required` 开头。
If no, just write "NONE" in the release-note block below.
If yes, a release note is required:
Enter your extended release note in the block below. If the PR requires additional action from users switching to the new release, include the string "action required".
-->
```release-note
None
```
Signed-off-by: Ryan Wang <i@ryanc.cc>
<!-- Thanks for sending a pull request! Here are some tips for you:
1. 如果这是你的第一次，请阅读我们的贡献指南：<https://github.com/halo-dev/halo/blob/master/CONTRIBUTING.md>。
1. If this is your first time, please read our contributor guidelines: <https://github.com/halo-dev/halo/blob/master/CONTRIBUTING.md>.
2. 请根据你解决问题的类型为 Pull Request 添加合适的标签。
2. Please label this pull request according to what type of issue you are addressing, especially if this is a release targeted pull request.
3. 请确保你已经添加并运行了适当的测试。
3. Ensure you have added or ran the appropriate tests for your PR.
-->
#### What type of PR is this?
/kind feature
/milestone 2.0
<!--
添加其中一个类别：
Add one of the following kinds:
/kind bug
/kind cleanup
/kind documentation
/kind feature
/kind optimization
适当添加其中一个或多个类别（可选）：
Optionally add one or more of the following kinds if applicable:
/kind api-change
/kind deprecation
/kind failing-test
/kind flake
/kind regression
-->
#### What this PR does / why we need it:
为主题添加设置表单支持，适配 https://github.com/halo-dev/halo/pull/2299
/hold until https://github.com/halo-dev/halo/pull/2299 merge
#### Which issue(s) this PR fixes:
Fixes https://github.com/halo-dev/halo/issues/2298
<!--
PR 合并时自动关闭 issue。
Automatically closes linked issue when PR is merged.
用法：`Fixes #<issue 号>`，或者 `Fixes (粘贴 issue 完整链接)`
Usage: `Fixes #<issue number>`, or `Fixes (paste link of issue)`.
-->
#### Screenshots:
|<img width="1564" alt="image" src="https://user-images.githubusercontent.com/21301288/182583412-f14a890e-25ee-418c-b921-0924f94c0d1b.png">|<img width="1564" alt="image" src="https://user-images.githubusercontent.com/21301288/182583525-26fe165c-2dd0-4068-9d52-659dc626367a.png">|
| ---- | ---- |
<!--
如果此 PR 有 UI 的改动，最好截图说明这个 PR 的改动。
If there are UI changes to this PR, it is best to take a screenshot to illustrate the changes to this PR.
eg.
Before:
After:
-->
#### Special notes for your reviewer:
测试方式：
1. Halo 后端需要 checkout 到 https://github.com/halo-dev/halo/pull/2299 分支。
2. 将被测主题放置在 `~/halo-next/themes`，可以使用 https://github.com/ruibaby/theme-astro-starter
3. 使用主题内的 `theme.yaml` 和 `settings.yaml` 创建 `Theme` 和 `Setting` 的资源。
4. admin 需要 checkout 到当前 PR 的分支，启动开发服务之后在主题列表即可启用该主题。
5. 测试保存和更新主题配置。
#### Does this PR introduce a user-facing change?
<!--
如果当前 Pull Request 的修改不会造成用户侧的任何变更，在 `release-note` 代码块儿中填写 `NONE`。
否则请填写用户侧能够理解的 Release Note。如果当前 Pull Request 包含破坏性更新（Break Change），
Release Note 需要以 `action required` 开头。
If no, just write "NONE" in the release-note block below.
If yes, a release note is required:
Enter your extended release note in the block below. If the PR requires additional action from users switching to the new release, include the string "action required".
-->
```release-note
None
```
Ryan Wang
