feat(worker): add ability to manage workers

[wass3rw3rk]

adds ability to:

• view worker(s)
• update workers (platform admin only)
• add workers (platform admin only)

dependent on:
go-vela/sdk-go#218
go-vela/worker#457
go-vela/server#798

also, needs docs PR

[codecov]

Codecov Report

Merging #430 (6d2e4b6) into main (4612e32) will increase coverage by 0.62%.
The diff coverage is 95.10%.

@@            Coverage Diff             @@
##             main     #430      +/-   ##
==========================================
+ Coverage   85.38%   86.00%   +0.62%     
==========================================
  Files         122      132      +10     
  Lines        5386     5754     +368     
==========================================
+ Hits         4599     4949     +350     
- Misses        648      660      +12     
- Partials      139      145       +6     

Impacted Files	Coverage Δ
action/repo/get.go	93.61% <ø> (ø)
command/worker/get.go	73.91% <73.91%> (ø)
command/worker/add.go	88.00% <88.00%> (ø)
command/worker/view.go	88.00% <88.00%> (ø)
command/worker/update.go	88.46% <88.46%> (ø)
action/worker/get.go	92.30% <92.30%> (ø)
action/worker/add.go	100.00% <100.00%> (ø)
action/worker/table.go	100.00% <100.00%> (ø)
action/worker/update.go	100.00% <100.00%> (ø)
action/worker/validate.go	100.00% <100.00%> (ø)
... and 1 more

[plyr4]

LGTM, just some very minor wording tweaks

[ecrupper]

Nice