Fix template generation details

[smoy]

What changed?

• template_type is on line 1, template_schema_url is on on line 2
• If there resource is only a single account, don't use the variables.

Rationale

• The previous fix although fix the sort stability, the implementation details always put template_schema_url on first line.
• We have feedback that template looks strange when the resource is only a single account. Then literal is more understandable when its only a single account.

How was it tested?

If it was manually verified, list the instructions for your reviewers to follow.

• [x] Unit Tests
• [ ] Functional Tests
• [x] Manually Verified

Run import on iambic-templates-example to see the single account is now using literal.

[codecov[bot]]

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.03% :tada:

Comparison is base (fe9186c) 83.77% compared to head (cbac5ae) 83.80%. Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #566 +/- ## ========================================== + Coverage 83.77% 83.80% +0.03% ========================================== Files 105 105 Lines 12298 12321 +23 ========================================== + Hits 10303 10326 +23 Misses 1995 1995 ``` | Flag | Coverage Δ | | |---|---|---| | functional_tests | `65.97% <92.85%> (-0.10%)` | :arrow_down: | | functional_tests_config_discovery | `46.18% <92.85%> (+0.08%)` | :arrow_up: | | unit_tests | `74.10% <100.00%> (+0.08%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=noqdev#carryforward-flags-in-the-pull-request-comment) to find out more. | [Files Changed](https://app.codecov.io/gh/noqdev/iambic/pull/566?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=noqdev) | Coverage Δ | | |---|---|---| | [iambic/core/models.py](https://app.codecov.io/gh/noqdev/iambic/pull/566?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=noqdev#diff-aWFtYmljL2NvcmUvbW9kZWxzLnB5) | `90.35% <100.00%> (+0.62%)` | :arrow_up: | | [iambic/core/template\_generation.py](https://app.codecov.io/gh/noqdev/iambic/pull/566?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=noqdev#diff-aWFtYmljL2NvcmUvdGVtcGxhdGVfZ2VuZXJhdGlvbi5weQ==) | `88.80% <100.00%> (+0.20%)` | :arrow_up: | ... and [1 file with indirect coverage changes](https://app.codecov.io/gh/noqdev/iambic/pull/566/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=noqdev)

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