Take usage of URI fragments

[C0ffeeCode]

Description

It would be handy if we could launch Cinny opening a room automatically.
This would also enable the matrix.to project to add support for Cinny if they would like to do so.

To preserve privacy and room ids etc. to be leaked to the hosting service unnecessarily this leverages URI fragments over URI queries or paths.
Paths and queries are being sent to the server, which is not required in this scenario, while fragments are not.

Element handles this "issue" similarly.

Schema

dev.cinny.in/

• #/room/[roomid]
• #/room/[roomid]/[eventid]
• #/[spaceid]
• #/[spaceid]/[roomid]
• #/join/[roomid]

Fixes #170
Depends on #401

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

Preview: https://627cc9bb10a88f43bce051f0--pr-cinny.netlify.app
⚠️ Exercise caution. Use test accounts. ⚠️

[3nt3]

I created a PR to add cinny to the list of clients in https://matrix.to but it would be better UX if you could directly go the room instead of copy-pasting it into the client.

BTW: how should we handly copyright attribution of the cinny logo?

[theotheroracle]

as this pr's dependency was merged, is there anything it's currently waiting on ?

[greentore]

Typo. Should be:
if (!selectedRoom) pieces.length = 2;

[github-actions]

CLA Assistant Lite bot:
Thank you for your submission, we really appreciate it. Like many open-source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution. You can sign the CLA by just posting a Pull Request Comment same as the below format.

---

I have read the CLA Document and I hereby sign the CLA

---

_{You can retrigger this bot by commenting recheck in this Pull Request}

[github-actions]

Preview: https://411--pr-cinny.netlify.app
⚠️ Exercise caution. Use test accounts. ⚠️

[fnwbr]

Thank you a lot for the continued efforts on this.

I just tested the netlify-hosted version of this PR, and it's shaping up really nicely!
Some things that I noticed that don't work:

• Using "back" and "forward" history buttons in the browser don't do anything
• Opening a new window / new session of Cinny and navigating to a room right away, e.g. by clicking on a link such as https://411--pr-cinny.netlify.app/#/room/#cinny:matrix.org will show you the default welcome screen instead of the room you intended to navigate to

[aceArt-GmbH]

• Opening a new window / new session of Cinny and navigating to a room right away, e.g. by clicking on a link such as https://411--pr-cinny.netlify.app/#/room/#cinny:matrix.org will show you the default welcome screen instead of the room you intended to navigate to

https://github.com/cinnyapp/cinny/pull/411/files#diff-cc58d91e2c920c0129c91191387a190b861bb84e12775c6f729ddcda65ce1f1fR40-R44 seems to be the problem. No code after is executed

With it removed, "back" and "forward" work too

cc #70 #108

[kfiven]

Closing in favour of #1633 adding the URL navigation.