Remove TSLint in favor of ESLint

[traeok]

Describe the bug

Not necessarily a bug, but TSLint is now deprecated and should be replaced with ESLint. Since we are already using ESLint we can remove references to TSLint and merge any TSLint rules into the ESLint config.

Expected behavior

zowe-explorer package only uses ESLint as the linter and will no longer use TSLint.

[github-actions]

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