Replace all share buttons with copy link buttons

### Your use case

#### What would you like to do?

Replace all share buttons in the app with copy link buttons.

#### Why would you like to do it?

For reference, the current share dialog:


Opening a share dialog just adds an extra step to what I really want to do 99% of the time, which is to copy the link. I know that the share button on messages can be right-clicked to copy the link, but that also requires the same number of clicks, plus the cognitive load of looking through my browser's context menu for the correct option. That shortcut is also not very discoverable for new users.

I've never used any of the social media shortcuts in the share dialog, since they inevitably fail to encompass the channels that I *actually* share Matrix links through, and I always feel wary that share templates will require more effort to use than just pasting a link into the correct communication channel manually. To me, they add no value, but I have no idea whether others find them useful.

In theory, the QR code seems like something I might use, but in practice I never have.

### Have you considered any alternatives?

- Not removing the share dialog if others do, in fact, value the QR code and social media options
- Adding a copy link button alongside the share button on messages

### Additional context

I'm not aware of other instant messengers that have more than just a 'copy link' button on messages.

Related: https://github.com/vector-im/element-web/issues/7187, https://github.com/vector-im/element-web/issues/6909, https://github.com/vector-im/element-web/issues/15562, https://github.com/vector-im/element-web/issues/18642