Fix typescript-ts-mode indentation (bug#77803)

Fix typescript-ts-mode indentation (bug#77803)

Don't align variable names to their declaratory expression.

Before this commit in code like:

    const a = 1,
          b = 2;

the b would get indented to `const'.  Similarly for `var' and
`let'. The expected behavior instead is getting indented to
`typescript-ts-mode-indent-offset'.

* lisp/progmodes/typescript-ts-mode.el
(typescript-ts-mode--indent-rules): Indent identifiers declarations to
`typescript-ts-mode-indent-offset'.
* test/lisp/progmodes/typescript-ts-mode-resources/indent.erts
(Lexical and variable declarations): Update test accordingly.