#### Why I did it
Currently, SONiC use a single value to represent SFP error, however, multiple SFP errors could exist at the same time. This PR is aimed to support it
#### How I did it
Return bitmap instead of single value when a SFP event occurs
Signed-off-by: Stephen Sun <stephens@nvidia.com>
Originally, SFP modules were always accessed from platform daemons, and arbitrary SFP modules can be accessed in the daemon. So all SFP modules were initialized in one shot once one of the following chassis APIs called
- get_all_sfps
- get_sfp_numbers
- get_sfp
Recently, we noticed that SFP modules can also be accessed from CLI, eg. the latest refactor of `sfputil`.
In this case, only one SFP module is accessed in the chassis object's life cycle.
To initialize all SFP modules in one shot is waste of time and causes the CLI to take much more time to finish.
So we would like to optimize the initialization flow by introducing a two-phase initialization approach:
- Partial initialization, which means the `chassis._sfp_list` has been initialized with proper length and all elements being `None`
- Full initialization, which means all elements in `chassis._sfp_list` are created
If the relevant function is called,
- `get_sfp`, only partial initialization will be done, and then the specific SFP module is initialized.
- `get_all_sfps` or `get_num_sfps`, full initialization will be done, which means all SFP modules are initialized.
Signed-off-by: Stephen Sun <stephens@nvidia.com>
