Create container with environment variables

[mgjm]

What type of PR is this?

/kind feature

What this PR does / why we need it:

Add an option to pass environment variables to the OCI runtime.

type CreateContainerConfig struct {
	// ...

	// EnvVars are the environment variables passed to the create runtime call.
	EnvVars map[string]string
}

Update: I extended this PR to also add the same option to ExecSyncConfig.

Which issue(s) this PR fixes:

None

Special notes for your reviewer:

This PR depends on #1498 for the new TextTextMap capnp type and helper functions.

b4e18e1 is the new commit in this PR
2224dd6 does the same for ExecSync

Does this PR introduce a user-facing change?

Add an option to pass environment variables to the OCI runtime

[codecov-commenter]

Codecov Report

Merging #1499 (b4e18e1) into main (f132a00) will decrease coverage by 0.18%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1499      +/-   ##
==========================================
- Coverage   34.18%   34.00%   -0.18%     
==========================================
  Files          13       13              
  Lines        1135     1135              
  Branches      392      390       -2     
==========================================
- Hits          388      386       -2     
  Misses        493      493              
- Partials      254      256       +2     

[haircommander]

/hold

for #1498

[mgjm]

Closed by accident (during rebase), and #1498 is merged now

[rphillips]

/hold cancel
/lgtm

[haircommander]

/approve

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: haircommander, mgjm

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [haircommander]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment