[enhancement] Harmonize names of flags meaning the same thing

### What's hard to do? (limit 100 words)

Semantically similar flags have different names in various binaries: Say the main output of a binay:

* `ir_converter_main` uses `--output_file` for its main output
* `opt_main` calls its output `--output_path`
* `codegen_main` uses `--output_verilog_path` (it has a bunch of other output flags for other side outputs, which are probably good names but the main output should be easily discoverable)

Or the standlib path
* `ir_converter_main` and `interpreter_main` use `--dslx_stdlib_path` while `dslx_ls` uses `--stdlib_path`

### Current best alternative workaround (limit 100 words)

The main output of binaries should probably be harmonized to a short `-o` option which is the discoverable name for anyone using any kind of Unix tool.

The standard-lib path should probably be `--dslx_stdlib_path`.

There probably needs to be a fallback support for the old flags, wich loud warnings that it will go away and then eventually removing the old flags.

### Your view of the "best case XLS enhancement" (limit 100 words)

Use `-o` for main outputs. Use `--dslx_stdlib_path` for stdlib.

This issue is not exhaustive: There are probably more flags in main binaries that should be surveyed to see if the semantically same thing is called the same.