codegen: move templates comments from generated code

[a8m]

Template comments should not be included in the generated assets (it repeats itself for every arg).

cc @giautm

[coveralls]

coverage: 73.889% (-0.03%) from 73.915%
when pulling 0f87d1d on templcomment
into 4b06405 on master.

[a8m]

Also, something a bit worrying is that the latest upgrade significantly increases the size of the generated code. See this PR as an example (from 15K to 21K): https://github.com/ent/contrib/pull/607/files

[StevenACoffman]

Ah, oops. Yeah, that's a good call. Not sure about the codegen size increase source (just more comments?).

[a8m]

Not sure about the codegen size increase source (just more comments?).

See the PR example I shared above.

[StevenACoffman]

Sorry, I was unclear in my comment.
In https://github.com/ent/contrib/pull/607/files github.com/99designs/gqlgen was moved from v0.17.48 to v0.17.51

In that PR, I see that entgql/internal/todo/generated.go went from 15K to 21K lines, but it was not clear to me if the comments fully accounted for the difference and this PR fully fixes the issue.

[StevenACoffman]

@a8m @michaelcaulley @vitorfalcaor Thanks for your work!

Also in https://github.com/ent/contrib/pull/607/files github.com/99designs/gqlgen was moved from v0.17.48 to v0.17.51.

I see that in that PR it has a comment that says that gqlgen version v0.17.52 has an issue with ent field collection. It blames commit: f81239e

The blamed gqlgen commit was merged #3287
This was to fix #3285 by reverting #3203

Currently gqlgen v0.17.61 is the latest. It is not clear to me if there remains any problem with gqlgen and ent field collection.
Please point me to an open issue in gqlgen (or PR) describing (or fixing) the ent field collection problem.