feat(no-template-literal-title): disallow template literals in titles

[unlikelyzero]

Closes #499

Adds no-template-literal-title, which reports a template literal used as the
title of test, test.describe, or test.step.

A test title is an identifier — reporters group by it, --grep matches it, and
flake dashboards key on it. Interpolating a value means the title only exists
once the data does, and changes when the data changes: --grep "login as admin"
matches nothing predictable from the source, and a title that reads
upload invoice-8842.pdf on one run is a different test to anything tracking
results over time.

The rule splits that into two reports, because the two cases deserve different
treatment:

Case	Message	Fix
test(`login as ${role}`)	interpolatedTitle	none — the right replacement is the author's call
test(`checkout completes`)	staticTemplateLiteral	autofixed to 'checkout completes'

The fixer escapes \ and ', and declines to fix multiline titles or ones
whose cooked value is null (invalid escape sequence), so it can never change
the name that ends up in a report.

Options

ignore: Array<'test' | 'test.describe' | 'test.step'> skips the listed
callers, mirroring the ignore option on prefer-lowercase-title. A suite that
deliberately generates parameterized test names can set { ignore: ['test'] }
and still get stable test.describe and test.step titles.

Not added to the recommended config — parameterized titles are an established
Playwright pattern, so whether to forbid them is a project-level policy choice.

Tests

34 cases covering modifiers (.only, .skip, .fixme, .describe.only),
globalAliases, fixer escaping of backticks/quotes/backslashes, the unfixable
multiline case, both option paths, and the negatives — anonymous
test.describe(() => {}), string concatenation, and template literals in
locators or test.describe.configure().