Add full_name shortcut for Chat

[Olegt0rr]

Description

In some cases it's handy to get user's current params via get_chat method.
Then you want to use full_name shortcut similar to User, but it's absent for Chat... :(

So, may be add it? :)

Type of change

Please delete options that are not relevant.

• Ported 2.x feature (non-breaking change which adds functionality)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[github-actions]

✔️ Changelog found.

Thank you for adding a description of the changes

[codecov]

Codecov Report

Merging #929 (d53626e) into dev-3.x (adfc89f) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##           dev-3.x      #929   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          300       300           
  Lines         8184      8191    +7     
=========================================
+ Hits          8184      8191    +7     

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
aiogram/types/chat.py	100.00% <100.00%> (ø)

[evgfilim1]

Question to maintainers: What's better in your opinion, past tense like this (Added ...) or present tense like in commit messages (Add ...)? I personally prefer the latter.

[JrooTJunior]

I prefer the former because change log is historical data

Present tense looks like TODO list with unfinished tasks:

Update v1:

• Add foo

Update v2:

• Fix bar

Past tense looks like a list of things already done:

Update v1:

• Added foo

Update v2:

• Fixed bar