Change working directory to .halo2 (#2728)

#### What type of PR is this?

/kind improvement
/area core
/milestone 2.0.0

#### What this PR does / why we need it:

See https://github.com/halo-dev/halo/issues/2727 for more.

#### Which issue(s) this PR fixes:

Fixes https://github.com/halo-dev/halo/issues/2727

#### Does this PR introduce a user-facing change?

```release-note
None
```

src/main/resources/application-dev.yaml

@@ -22,6 +22,7 @@ halo:
       - "build/resources"
     lib-directories:
       - "libs"
+  work-dir: ${user.home}/halo2-dev
 logging:
   level:
     run.halo.app: DEBUG

src/main/resources/application.yaml

@@ -22,7 +22,7 @@ halo:
       jwt:
         public-key-location: classpath:app.pub
         private-key-location: classpath:app.key
-  work-dir: ${user.home}/halo-next
+  work-dir: ${user.home}/.halo2
   plugin:
     plugins-root: ${halo.work-dir}/plugins
 

src/main/resources/extensions/attachment-local-policy.yaml

@@ -19,4 +19,4 @@ spec:
         - $formkit: text
           name: location
           label: 存储位置
-          help: ~/halo-next/attachments 下的子目录
+          help: ~/.halo2/attachments 下的子目录