feat: support bun

[km1chno]

Resolves #87

Changes

• extend PackageManager type with bun,
• detect bun as package manager based on presence of bun.lockb file ,
• dependencies extension uses bun install if bun is detected as package manager,
• added analogue to mechanism of detecting node version and creating .nvmrc if not found: in case of bun, we look for .bun-version file and create it if not detected (with the currently latest version 1.1.30)
• small refactor in templates, extracted install commands and "Setup Node" steps to common templated that is included
• extended extracted sub-templates with options for bun (install command and "Setup bun" step instead of "Setup node")
• created new test project rn-setup-ci-create-expo-stack-bun generated with create-expo-stack --bun and added it to our suite
• created new test suite runtime-version-file.test.ts with tests for creating .nvmrc and .bun-version files