Clarify cmd processing success event text for cases that just initialize action

[skliper]

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• I reviewed the CF README.md file to see if the feature is in the major future work.
• I performed a cursory search to see if the feature request is relevant, not redundant, nor in conflict with other tickets.

Is your feature request related to a problem? Please describe.
Playback, transfer, and cancel commands just initiate the action which is then handled by the engine. Event text implies otherwise:

CF/fsw/src/cf_cmd.c

Line 168 in 557c132

CFE_EVS_SendEvent(CF_EID_INF_CMD_TX_FILE, CFE_EVS_EventType_INFORMATION, "CF: file transfer successful");

CF/fsw/src/cf_cmd.c

Lines 211 to 212 in 557c132

	CFE_EVS_SendEvent(CF_EID_INF_CMD_PLAYBACK_DIR, CFE_EVS_EventType_INFORMATION,
	"CF: directory playback successful");

CF/fsw/src/cf_cmd.c

Line 515 in 557c132

CFE_EVS_SendEvent(CF_EID_INF_CMD_CANCEL, CFE_EVS_EventType_INFORMATION, "CF: cancel successful");

Describe the solution you'd like
Update text to indicate the action was successfully initiated

Describe alternatives you've considered
None

Additional context
None

Requester Info
Jacob Hageman - NASA/GSFC