feat: implement custom remote backend

[panekj]

Closes #1467
Closes #1827
Closes #1481
Closes #1557

• Added an entry to CHANGELOG.md if this change could be valuable to users

[codecov-commenter]

Codecov Report

Merging #2165 (52ed970) into master (b92c519) will decrease coverage by 0.02%.
The diff coverage is 0.00%.

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@@            Coverage Diff            @@
##           master   #2165      +/-   ##
=========================================
- Coverage    8.93%   8.91%   -0.02%     
=========================================
  Files         136     136              
  Lines       59293   59399     +106     
=========================================
+ Hits         5295    5296       +1     
- Misses      53998   54103     +105     

Impacted Files	Coverage Δ
lapce-data/src/command.rs	0.00% <ø> (ø)
lapce-data/src/config.rs	0.00% <0.00%> (ø)
lapce-data/src/data.rs	0.00% <0.00%> (ø)
lapce-data/src/palette.rs	3.91% <0.00%> (-0.15%)	⬇️
lapce-data/src/proxy.rs	0.00% <0.00%> (ø)
lapce-ui/src/palette.rs	0.00% <0.00%> (ø)
lapce-ui/src/tab.rs	0.00% <0.00%> (ø)
lapce-ui/src/title.rs	0.00% <0.00%> (ø)
lapce-data/src/keypress/keypress.rs	73.23% <0.00%> (+0.20%)	⬆️

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[thomasaarholt]

Will this PR allow vscode-like "attach to running container" style connections? Those are used for connecting into docker containers. I see you're closing #1481 - are there more steps required to enable connecting to containers?