feat: move to Typescript code generation

[xiaozhenliu-gg5]

No description provided.

[codecov]

Codecov Report

Merging #631 into master will increase coverage by 23.08%.
The diff coverage is 91.15%.

@@             Coverage Diff             @@
##           master     #631       +/-   ##
===========================================
+ Coverage   73.13%   96.22%   +23.08%     
===========================================
  Files          33       15       -18     
  Lines       15964    12499     -3465     
  Branches      586      786      +200     
===========================================
+ Hits        11676    12027      +351     
+ Misses       4288      469     -3819     
- Partials        0        3        +3

Impacted Files	Coverage Δ
src/v2/index.ts	100% <100%> (ø)
src/v2/bigtable_client.ts	91.32% <90.82%> (ø)
src/v2/bigtable_instance_admin_client.ts	91.1% <91.1%> (ø)
src/v2/bigtable_table_admin_client.ts	91.2% <91.2%> (ø)

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[xiaozhenliu-gg5]

Send out cl/299452868 for fixing the timeout setting in admin/v2 which blocks system-test. Other than that, all tests are green.

[bcoe]

This looks good to me, but we should loop in @steffnay as well.

Given the popularity of this library, I would love to see if someone like Steffany who's familiar with the library could help smoke test a bit, or recommend some smoke testing we could perform.

[steffnay]

@xiaozhenliu-gg5 @bcoe This looks good to me. I'm actually not super familiar with this library, though, so I don't think I can be much help with the tests

[summer-ji-eng]

LGTM

[alexander-fenster]

@xiaozhenliu-gg5 Please remove src/v2/.DS_Store from the change :)

[alexander-fenster]

LGTM with nits