[LINTER] Prevent using inline doxygen comments on their own line

Summary: This will prevent issues like D5180 to occur again.

Test Plan:
Add a few doxygen inline comments in a source file such as:

///< A comment
//!< another comment
/**< yet another comment */
/*!< my last comment */

Run arc lint and check the linter offers to replace with the
non-inline equivalent.

arc lint --everything

Reviewers: #bitcoin_abc, markblundeberg

Reviewed By: #bitcoin_abc, markblundeberg

Subscribers: markblundeberg

Differential Revision: https://reviews.bitcoinabc.org/D5203