--tags and --tag-only are not respected when --push=false is specified

## Bug Report

When running `build`, `resolve`, or `apply` with `--push=false`, the `-t` or `--tags` and `--tag-only` options are not respected.

### Expected Behavior

When `-t` or `--tags` option is used with `--push=false`, ko produces an image with the tag applied.
When the `--tag-only` option is used with `--push=false`, image references in `ko resolve` and `ko apply` reference images by tag (not sha).

### Actual Behavior

Only image shas are used in ko appy/resolve when `--push=false`.

### ko version

v0.11.2

Start by reproducing the behavior in the `build`, `resolve`, and `apply` entry points with `--push=false`, using both `--tags` and `--tag-only`. Trace how image references are formed in those paths; done means tags are preserved for `--tags`, and `ko resolve` and `ko apply` use tagged references rather than SHA references for `--tag-only`.

Written by the indexing model from the issue text.