feat: add max upload size setting to UI & UI improvements (#1646)

* Add preliminar Windows support for both
development and production environments.

Default profile.Data will be set to "C:\ProgramData\memos" on Windows.
Folder will be created if it does not exist, as this behavior is
expected for Windows applications.

System service installation can be achieved with third-party tools,
explained in docs/windows-service.md.

Not sure if it's worth using https://github.com/kardianos/service
to make service support built-in.

This could be a nice addition alongside #1583 (add Windows artifacts)

* feat: improve Windows support

- Fix local file storage path handling on Windows

- Improve Windows dev script

* feat: add max upload size setting to UI & more

- feat: add max upload size setting to UI

- feat: max upload size setting is checked on UI during upload,
but also enforced by the server

- fix: overflowing mobile layout for Create SSO, Create Storage
and other Settings dialogs

- feat: add HelpButton component with some links to docs were appropriate

- remove LearnMore component in favor of HelpButton

- refactor: change some if/else to switch statements

- refactor: inline some err == nil checks

! Existing databases without the new setting 'max-upload-size-mib'
will show an upload error, but this can be user-fixed by simply
setting the value on system settings UI.

* improvements requested by @boojack

api/system.go

@@ -14,6 +14,8 @@ type SystemStatus struct {
 	IgnoreUpgrade bool `json:"ignoreUpgrade"`
 	// Disable public memos.
 	DisablePublicMemos bool `json:"disablePublicMemos"`
+	// Max upload size.
+	MaxUploadSizeMiB int `json:"maxUploadSizeMiB"`
 	// Additional style.
 	AdditionalStyle string `json:"additionalStyle"`
 	// Additional script.