Link parsing, character encoding, and variable accessing errors when parsing complex room topics

[JakeSteam]

Rocket.Chat Version: 0.54.2

Setting the room topic to _[I'm $&](http://google.com)_ should produce underlined text "I'm $&" that links to Google.

Instead, it results in this mess in chat: __blank">I'm __room_topic__amp;_, and a slightly different one in the sidebar: https://i.imgur.com/dMa4O2Z.png

1. Underlining breaks the link parser, getting confused with the _blank target. Bad parameter escaping?
2. The apostrophe character is incorrectly encoded (applies to other characters too).
3. The $& sequence becomes __room_topic__amp;, indicating I'm getting some kind of access to internal variables, which I shouldn't be.

There's almostly certainly a lot more issues here.

[iangilfillan]

Confirming this is still an issue in 0.62.2

[iTob191]

Seems like this applies not only to room titles but to links in general. For example posting [a'b](https://hostname.tld) into the chat results in a link named a'b. Looks like the link text is encoded twice.

[gabriellsh]

Still happens 2.5.0-develop