allow operationId be ignored when generating operation names

[askvortcov]

Adds a CLI parameter --useOperationId, which allows using or ignoring OperationId in the swagger and relies on the path to generate operation names.

Use path placeholders to decorate operation names.

Ignoring operation ID is handy when working with a swagger generated by springdoc-openapi, since it generates messy operation IDs when confronted with multiple possibilities of Accept header.

resolves #1525

[mrlubos]

@askvortcov want to open this pull request against our fork?

[askvortcov]

@askvortcov want to open this pull request against our fork?

@mrlubos, Done. There is a merge conflict though. If I merge it it pulls too many commits along.

[mrlubos]

@askvortcov no worries, I will resolve it!