[MMO] Extend Sharing 2.3.1

Fix The Mastodon only comes on when Weibo is checked, if you uncheck Weibo then Mastodon goes away.
Fix missing span on xing
Fix viber share

Minimum XF version 2.3.0
Remove linkedin
Add mastodon

Support XF 2.3

Fix missing phrase
Change modification

Add support Xing
Add support Weibo
Added can add custom property for style buttons.
With the new option, for example, if you want to replace square icons with round ones, you can enter the corresponding CSS property in the style setting.
For example:
border-radius: 50%;