Refactor smtp provider lib

[arturo-seijas]

Applicable spec: N/A

Overview

Refactor smtp provider lib

Rationale

Remove from the SmtpProvider an attribute that conceptually belongs to the charm itself

Juju Events Changes

N/A

Module Changes

charm.py adapted to the lib changes

Library Changes

Removed the SmtpProvider relation property

Checklist

• The charm style guide was applied
• The contributing guide was applied
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation is generated using src-docs
• The documentation for charmhub is updated
• The PR is tagged with appropriate label (urgent, trivial, complex)

[github-actions]

Test coverage for 0a6eee0

Name                                    Stmts   Miss Branch BrPart  Cover   Missing
-----------------------------------------------------------------------------------
lib/charms/smtp_integrator/v0/smtp.py     116      2     20      2    97%   319, 321
src/charm.py                               59      2     16      2    95%   87, 89
src/charm_state.py                         46      0      6      0   100%
-----------------------------------------------------------------------------------
TOTAL                                     221      4     42      4    97%

Static code analysis report

Run started:2023-11-29 14:04:31.553015

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 802
  Total lines skipped (#nosec): 1
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 0

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):