Support unescaped variables in TypeScript when parsing actual values.

Without this fix, the variable names parsed in TypeScript will include the unescaped prefix/suffix, for example:

"locale": "Something {{- var}}"

t("locale", { "- var": value })

instead of:

t("locale", { var: value })

Checklist

• only relevant code is changed (make a diff before you submit the PR)
• run tests npm run test
• tests are included
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Checklist (for documentation change)

• only relevant documentation part is changed (make a diff before you submit the PR)
• motivation/reason is provided
• commit message and code follows the Developer's Certification of Origin